feat(refboard): canvas polish — transform box sync, dot grid, snap tuning, perf fixes

- Fix transform box not updating after alignment/arrangement/normalize/flip operations
  (shortcuts, context menu, and selection toolbar all fixed with DRY _opUpdate helper)
- Replace 100ms polling loop with event-driven viewport updates (moved + wheel-scroll)
- Add adaptive dot grid background that responds to zoom/pan
- Reduce snap guide threshold from 8px to 4px for subtler snapping
- Remove PresenceOverlay (remote selection highlighting) — too heavy for minimal benefit
- Offset multiple dropped images so they don't overlap
- Add new canvas modules: SnapGuides, clipboard, grouping, FrameSprite, DrawingSprite,
  LaserPointer, context-menu-items, SelectionToolbar, Minimap
- Extract Editor hooks into dedicated files (useBoardLoader, useCanvasSetup,
  useShortcutHandler, useLayerPanel, useSaveManager, useFollowMode)
- Sync improvements: real-time transform broadcast, board rooms, viewport sync

.dockerignore

@@ -0,0 +1,3 @@
+**/node_modules
+**/.git
+**/.env

backend/minio.js

@@ -116,6 +116,8 @@ function getImageUrl(minioPath) {
   return `/api/images/${minioPath}`;
 }
 
+const MAX_FILE_SIZE = parseInt(process.env.MAX_FILE_SIZE_MB || '200', 10) * 1024 * 1024;
+
 module.exports = {
   minioClient,
   initBucket,
@@ -126,4 +128,5 @@ module.exports = {
   getImageUrl,
   MINIO_BUCKET,
   MIME_TO_EXT,
+  MAX_FILE_SIZE,
 };

backend/routes/mattermost-bridge.js

@@ -7,7 +7,6 @@ const {
   createImage, getImageByMmFileId,
 } = require('../db');
 const { putBuffer, getImageUrl, MIME_TO_EXT } = require('../minio');
-const { generateLOD } = require('../services/lod-generator');
 const sharp = require('sharp');
 
 const router = Router();
@@ -94,44 +93,23 @@ function classifyMedia(mimeType) {
 }
 
 /**
- * Upload image buffer with LOD tiers to MinIO.
+ * Upload a media file (image or video) to MinIO as a single file.
+ * GPU handles all scaling natively — no LOD tiers needed.
  */
-async function uploadImageWithLOD(boardId, imageId, buffer, mimetype) {
+async function uploadMedia(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
+  const ext = MIME_TO_EXT[mimetype] || '.bin';
-  const originalExt = MIME_TO_EXT[mimetype] || '.bin';
+  const minioPath = `boards/${boardId}/${imageId}${ext}`;
+  await putBuffer(minioPath, buffer, mimetype);
 
-  if (mimetype === 'image/svg+xml' || mimetype === 'image/gif') {
+  let width = null, height = null;
-    const fullPath = `${assetKey}/full${originalExt}`;
+  if (mimetype !== 'image/svg+xml' && !mimetype.startsWith('video/')) {
-    await putBuffer(fullPath, buffer, mimetype);
-    let width = null, height = null;
     try {
       const metadata = await sharp(buffer).metadata();
       width = metadata.width || null;
       height = metadata.height || null;
     } catch {}
-    return { assetKey, minioPath: fullPath, width, height };
   }
-
+  return { assetKey: minioPath, minioPath, width, height };
-  const lod = await generateLOD(buffer, originalExt);
-  await Promise.all([
-    putBuffer(`${assetKey}/thumb${lod.thumb.ext}`, lod.thumb.buffer, lod.thumb.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/medium${lod.medium.ext}`, lod.medium.buffer, lod.medium.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/full${lod.full.ext}`, lod.full.buffer, mimetype),
-  ]);
-
-  const minioPath = `${assetKey}/full${lod.full.ext}`;
-  return { assetKey, minioPath, width: lod.full.width, height: lod.full.height };
-}
-
-/**
- * Upload video buffer to MinIO (no LOD).
- */
-async function uploadVideo(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
-  const ext = MIME_TO_EXT[mimetype] || '.bin';
-  const fullPath = `${assetKey}/full${ext}`;
-  await putBuffer(fullPath, buffer, mimetype);
-  return { assetKey, minioPath: fullPath, width: null, height: null };
 }
 
 // ---------------------
@@ -287,13 +265,7 @@ router.post('/:boardId/mm-pull', async (req, res) => {
         const imageId = uuidv4();
         const mediaType = classifyMedia(mimeType);
 
-        let assetKey, minioPath, width, height;
+        const { assetKey, minioPath, width, height } = await uploadMedia(board.id, imageId, buffer, mimeType);
-
-        if (mediaType === 'video') {
-          ({ assetKey, minioPath, width, height } = await uploadVideo(board.id, imageId, buffer, mimeType));
-        } else {
-          ({ assetKey, minioPath, width, height } = await uploadImageWithLOD(board.id, imageId, buffer, mimeType));
-        }
 
         const publicUrl = getImageUrl(minioPath);
 

backend/routes/upload.js

@@ -7,8 +7,7 @@ const http = require('http');
 const { URL } = require('url');
 const { authMiddleware } = require('../auth');
 const { getBoard, getCollectionMember, createImage } = require('../db');
-const { putBuffer, getImageUrl, MIME_TO_EXT } = require('../minio');
+const { putBuffer, getImageUrl, MIME_TO_EXT, MAX_FILE_SIZE } = require('../minio');
-const { generateLOD } = require('../services/lod-generator');
 
 const router = Router();
 
@@ -28,9 +27,9 @@ const VIDEO_MIME_TYPES = [
 
 const ALLOWED_MIME_TYPES = [...IMAGE_MIME_TYPES, ...VIDEO_MIME_TYPES];
 
-const MAX_FILE_SIZE = 50 * 1024 * 1024; // 50MB
+const MAX_FILE_SIZE_LABEL = `${MAX_FILE_SIZE / 1024 / 1024}MB`;
 
-// Multer config: memory storage, 50MB limit, image types only
+// Multer config: memory storage, configurable size limit
 const upload = multer({
   storage: multer.memoryStorage(),
   limits: { fileSize: MAX_FILE_SIZE },
@@ -90,46 +89,17 @@ function classifyMedia(mimeType) {
 }
 
 /**
- * Upload LOD tiers for an image to MinIO.
+ * Upload a media file (image or video) to MinIO as a single file.
- * Stores: {assetKey}/thumb.webp, {assetKey}/medium.webp, {assetKey}/full{ext}
+ * GPU handles all image scaling natively — no LOD tiers needed.
- * Returns the minioPath for the full tier (backward compat) and dimensions.
  */
-async function uploadImageWithLOD(boardId, imageId, buffer, mimetype) {
+async function uploadMedia(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
-  const originalExt = MIME_TO_EXT[mimetype] || '.bin';
-
-  // SVG and GIF skip LOD — store single file
-  if (mimetype === 'image/svg+xml' || mimetype === 'image/gif') {
-    const fullPath = `${assetKey}/full${originalExt}`;
-    await putBuffer(fullPath, buffer, mimetype);
-    const dims = await getImageDimensions(buffer, mimetype);
-    return { assetKey, minioPath: fullPath, ...dims };
-  }
-
-  const lod = await generateLOD(buffer, originalExt);
-
-  // Upload all 3 tiers in parallel
-  await Promise.all([
-    putBuffer(`${assetKey}/thumb${lod.thumb.ext}`, lod.thumb.buffer, lod.thumb.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/medium${lod.medium.ext}`, lod.medium.buffer, lod.medium.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/full${lod.full.ext}`, lod.full.buffer, mimetype),
-  ]);
-
-  // minioPath points to full tier for backward compat
-  const minioPath = `${assetKey}/full${lod.full.ext}`;
-  return { assetKey, minioPath, width: lod.full.width, height: lod.full.height };
-}
-
-/**
- * Upload a video file to MinIO (single file, no LOD).
- * Returns { assetKey, minioPath, width: null, height: null }.
- */
-async function uploadVideo(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
   const ext = MIME_TO_EXT[mimetype] || '.bin';
-  const fullPath = `${assetKey}/full${ext}`;
+  const minioPath = `boards/${boardId}/${imageId}${ext}`;
-  await putBuffer(fullPath, buffer, mimetype);
+  await putBuffer(minioPath, buffer, mimetype);
-  return { assetKey, minioPath: fullPath, width: null, height: null };
+
+  const dims = await getImageDimensions(buffer, mimetype);
+  // assetKey = minioPath so frontend can build direct URLs
+  return { assetKey: minioPath, minioPath, width: dims.width, height: dims.height };
 }
 
 /**
@@ -149,14 +119,7 @@ router.post('/boards/:boardId/images', upload.single('image'), async (req, res)
     const { buffer, originalname, mimetype, size } = req.file;
     const mediaType = classifyMedia(mimetype);
 
-    let assetKey, minioPath, width, height;
+    const { assetKey, minioPath, width, height } = await uploadMedia(board.id, imageId, buffer, mimetype);
-
-    if (mediaType === 'video') {
-      ({ assetKey, minioPath, width, height } = await uploadVideo(board.id, imageId, buffer, mimetype));
-    } else {
-      ({ assetKey, minioPath, width, height } = await uploadImageWithLOD(board.id, imageId, buffer, mimetype));
-    }
-
     const publicUrl = getImageUrl(minioPath);
 
     // Save record
@@ -188,7 +151,7 @@ router.post('/boards/:boardId/images', upload.single('image'), async (req, res)
     });
   } catch (err) {
     if (err.code === 'LIMIT_FILE_SIZE') {
-      return res.status(413).json({ error: 'File too large (max 50MB)' });
+      return res.status(413).json({ error: `File too large (max ${MAX_FILE_SIZE_LABEL})` });
     }
     console.error('[upload] error:', err);
     return res.status(500).json({ error: 'Internal server error' });
@@ -225,7 +188,7 @@ function downloadImage(imageUrl) {
         totalSize += chunk.length;
         if (totalSize > MAX_FILE_SIZE) {
           response.destroy();
-          return reject(new Error('Downloaded file too large (max 50MB)'));
+          return reject(new Error(`Downloaded file too large (max ${MAX_FILE_SIZE_LABEL})`));
         }
         chunks.push(chunk);
       });
@@ -261,14 +224,7 @@ router.post('/boards/:boardId/images/from-url', async (req, res) => {
     const imageId = uuidv4();
     const mediaType = classifyMedia(mimeType);
 
-    let assetKey, minioPath, width, height;
+    const { assetKey, minioPath, width, height } = await uploadMedia(board.id, imageId, buffer, mimeType);
-
-    if (mediaType === 'video') {
-      ({ assetKey, minioPath, width, height } = await uploadVideo(board.id, imageId, buffer, mimeType));
-    } else {
-      ({ assetKey, minioPath, width, height } = await uploadImageWithLOD(board.id, imageId, buffer, mimeType));
-    }
-
     const publicUrl = getImageUrl(minioPath);
 
     // Save record
@@ -311,7 +267,7 @@ router.post('/boards/:boardId/images/from-url', async (req, res) => {
 router.use((err, req, res, next) => {
   if (err instanceof multer.MulterError) {
     if (err.code === 'LIMIT_FILE_SIZE') {
-      return res.status(413).json({ error: 'File too large (max 50MB)' });
+      return res.status(413).json({ error: `File too large (max ${MAX_FILE_SIZE_LABEL})` });
     }
     return res.status(400).json({ error: err.message });
   }

backend/services/mm-watcher.js

@@ -12,8 +12,7 @@ const { URL } = require('url');
 const { v4: uuidv4 } = require('uuid');
 const sharp = require('sharp');
 const { getAllBoardChannelLinks, getImageByMmFileId, createImage, getBoard } = require('../db');
-const { putBuffer, getImageUrl, MIME_TO_EXT } = require('../minio');
+const { putBuffer, getImageUrl, MIME_TO_EXT, MAX_FILE_SIZE } = require('../minio');
-const { generateLOD } = require('./lod-generator');
 
 const MM_URL = process.env.MM_URL;
 const MM_BOT_TOKEN = process.env.MM_BOT_TOKEN;
@@ -87,7 +86,7 @@ function mmDownloadFile(fileId) {
       const contentType = (res.headers['content-type'] || 'application/octet-stream').split(';')[0].trim();
       const chunks = [];
       let totalSize = 0;
-      const MAX_SIZE = 50 * 1024 * 1024;
+      const MAX_SIZE = MAX_FILE_SIZE;
 
       res.on('data', (chunk) => {
         totalSize += chunk.length;
@@ -147,47 +146,23 @@ function classifyMedia(mimeType) {
 }
 
 /**
- * Upload image with LOD tiers (mirrors upload.js logic).
+ * Upload a media file (image or video) to MinIO as a single file.
+ * GPU handles all image scaling natively — no LOD tiers needed.
  */
-async function uploadImageWithLOD(boardId, imageId, buffer, mimetype) {
+async function uploadMedia(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
-  const originalExt = MIME_TO_EXT[mimetype] || '.bin';
-
-  if (mimetype === 'image/svg+xml' || mimetype === 'image/gif') {
-    const fullPath = `${assetKey}/full${originalExt}`;
-    await putBuffer(fullPath, buffer, mimetype);
-    let width = null, height = null;
-    if (mimetype !== 'image/svg+xml') {
-      try {
-        const meta = await sharp(buffer).metadata();
-        width = meta.width || null;
-        height = meta.height || null;
-      } catch {}
-    }
-    return { assetKey, minioPath: fullPath, width, height };
-  }
-
-  const lod = await generateLOD(buffer, originalExt);
-
-  await Promise.all([
-    putBuffer(`${assetKey}/thumb${lod.thumb.ext}`, lod.thumb.buffer, lod.thumb.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/medium${lod.medium.ext}`, lod.medium.buffer, lod.medium.ext === '.webp' ? 'image/webp' : mimetype),
-    putBuffer(`${assetKey}/full${lod.full.ext}`, lod.full.buffer, mimetype),
-  ]);
-
-  const minioPath = `${assetKey}/full${lod.full.ext}`;
-  return { assetKey, minioPath, width: lod.full.width, height: lod.full.height };
-}
-
-/**
- * Upload a video file (single file, no LOD).
- */
-async function uploadVideo(boardId, imageId, buffer, mimetype) {
-  const assetKey = `boards/${boardId}/${imageId}`;
   const ext = MIME_TO_EXT[mimetype] || '.bin';
-  const fullPath = `${assetKey}/full${ext}`;
+  const minioPath = `boards/${boardId}/${imageId}${ext}`;
-  await putBuffer(fullPath, buffer, mimetype);
+  await putBuffer(minioPath, buffer, mimetype);
-  return { assetKey, minioPath: fullPath, width: null, height: null };
+
+  let width = null, height = null;
+  if (mimetype !== 'image/svg+xml' && !mimetype.startsWith('video/')) {
+    try {
+      const meta = await sharp(buffer).metadata();
+      width = meta.width || null;
+      height = meta.height || null;
+    } catch {}
+  }
+  return { assetKey: minioPath, minioPath, width, height };
 }
 
 /**
@@ -239,13 +214,7 @@ async function processLink(link) {
         const imageId = uuidv4();
         const mediaType = classifyMedia(mimeType);
 
-        let assetKey, minioPath, width, height;
+        const { assetKey, minioPath, width, height } = await uploadMedia(boardId, imageId, buffer, mimeType);
-
-        if (mediaType === 'video') {
-          ({ assetKey, minioPath, width, height } = await uploadVideo(boardId, imageId, buffer, mimeType));
-        } else {
-          ({ assetKey, minioPath, width, height } = await uploadImageWithLOD(boardId, imageId, buffer, mimeType));
-        }
 
         const publicUrl = getImageUrl(minioPath);
 

backend/socket/board-room.js

@@ -79,6 +79,26 @@ function setupBoardRoom(io, socket) {
     });
   });
 
+  // ---- Incremental element sync (Excalidraw-style) ----
+
+  socket.on('element:update', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.to(roomName).emit('element:update', {
+      ...data,
+      userId: socket.userId,
+    });
+  });
+
+  socket.on('element:remove', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.to(roomName).emit('element:remove', {
+      ...data,
+      userId: socket.userId,
+    });
+  });
+
   // ---- Lightweight transform (during drag/resize/rotate) ----
 
   socket.on('object:transform', (data) => {
@@ -102,6 +122,32 @@ function setupBoardRoom(io, socket) {
     });
   });
 
+  // ---- Selection presence (broadcast what items a user has selected) ----
+
+  socket.on('selection:update', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.volatile.to(roomName).emit('selection:update', {
+      ...data,
+      userId: socket.userId,
+      displayName: socket.userDisplayName,
+    });
+  });
+
+  // ---- Laser pointer ----
+
+  socket.on('laser:move', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.volatile.to(roomName).emit('laser:move', { ...data, userId: socket.userId });
+  });
+
+  socket.on('laser:stop', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.to(roomName).emit('laser:stop', { ...data, userId: socket.userId });
+  });
+
   // ---- Disconnect cleanup ----
 
   socket.on('disconnect', () => {

backend/socket/index.js

@@ -2,6 +2,7 @@ const { Server } = require('socket.io');
 const { verifyToken } = require('../auth');
 const { getUserById } = require('../db');
 const { setupBoardRoom } = require('./board-room');
+const { setupViewportSync } = require('./viewport-sync');
 
 /**
  * Set up Socket.IO on the given HTTP server.
@@ -49,6 +50,7 @@ function setupSocket(httpServer) {
 
     // Set up board room handlers
     setupBoardRoom(io, socket);
+    setupViewportSync(io, socket);
 
     socket.on('disconnect', (reason) => {
       console.log(`[socket] User disconnected: ${socket.userDisplayName} (${reason})`);

backend/socket/viewport-sync.js

@@ -0,0 +1,48 @@
+/**
+ * Viewport sync relay — broadcasts user viewport positions for follow mode.
+ * Each user periodically emits their viewport state; this relays it to
+ * everyone else in the same board room so followers can track in real-time.
+ *
+ * Kept separate from board-room.js to avoid conflicts.
+ */
+
+function getRoomName(boardId) {
+  return `board:${boardId}`;
+}
+
+function setupViewportSync(io, socket) {
+  // Relay viewport position to other users in the same board room
+  socket.on('viewport:sync', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.volatile.to(roomName).emit('viewport:sync', {
+      ...data,
+      userId: socket.userId,
+    });
+  });
+
+  // follow:start / follow:stop are informational — the server doesn't need
+  // to gate viewport:sync relay (all users broadcast always, clients filter).
+  // These events exist so the UI can show "X is following you" if desired.
+  socket.on('follow:start', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.to(roomName).emit('follow:start', {
+      boardId: data.boardId,
+      followerId: socket.userId,
+      followerName: socket.userDisplayName,
+      targetUserId: data.targetUserId,
+    });
+  });
+
+  socket.on('follow:stop', (data) => {
+    if (!socket.currentBoardId) return;
+    const roomName = getRoomName(socket.currentBoardId);
+    socket.to(roomName).emit('follow:stop', {
+      boardId: data.boardId,
+      followerId: socket.userId,
+    });
+  });
+}
+
+module.exports = { setupViewportSync };

frontend/src/canvas/InboxZone.ts

@@ -141,8 +141,8 @@ export class InboxZone extends Container {
       sprite.width = sw;
       sprite.height = sh;
 
-      // Load thumbnail texture
+      // Load texture (GPU handles scaling)
-      this.textures.load(assetKey, 'thumb').then((tex) => {
+      this.textures.load(assetKey).then((tex) => {
         if (!sprite.destroyed) {
           sprite.texture = tex;
           sprite.width = sw;

frontend/src/canvas/LaserPointer.ts

@@ -0,0 +1,202 @@
+import { Graphics } from 'pixi.js';
+import type { Viewport } from 'pixi-viewport';
+
+interface LaserPoint {
+  x: number;
+  y: number;
+  t: number;
+}
+
+export class LaserPointer {
+  private _gfx: Graphics;
+  private _viewport: Viewport;
+  private _points: LaserPoint[] = [];
+  private _active = false;
+  private _rafId: number | null = null;
+  private _color: number;
+  private _fadeMs = 2000;
+  private _maxPoints = 200;
+
+  // Remote user lasers
+  private _remoteGfx: Map<string, Graphics> = new Map();
+  private _remotePoints: Map<string, LaserPoint[]> = new Map();
+
+  constructor(viewport: Viewport, color: number = 0xff4444) {
+    this._viewport = viewport;
+    this._color = color;
+    this._gfx = new Graphics();
+    this._gfx.label = '__laser_local';
+    viewport.addChild(this._gfx);
+  }
+
+  get isActive(): boolean {
+    return this._active;
+  }
+
+  /** Begin recording trail, start render loop */
+  start(): void {
+    this._active = true;
+    if (this._rafId === null) {
+      this._tick();
+    }
+  }
+
+  /** Stop recording, let trail fade naturally, stop loop when empty */
+  stop(): void {
+    this._active = false;
+    // Render loop continues until all points have faded
+  }
+
+  /** Add a local laser point with current timestamp */
+  addPoint(worldX: number, worldY: number): void {
+    this._points.push({ x: worldX, y: worldY, t: performance.now() });
+    if (this._points.length > this._maxPoints) {
+      this._points.shift();
+    }
+  }
+
+  /** Add points from a remote user's laser */
+  addRemotePoints(
+    userId: string,
+    points: { x: number; y: number }[],
+    color: number,
+  ): void {
+    const now = performance.now();
+
+    if (!this._remoteGfx.has(userId)) {
+      const gfx = new Graphics();
+      gfx.label = `__laser_remote_${userId}`;
+      this._viewport.addChild(gfx);
+      this._remoteGfx.set(userId, gfx);
+    }
+
+    let arr = this._remotePoints.get(userId);
+    if (!arr) {
+      arr = [];
+      this._remotePoints.set(userId, arr);
+    }
+
+    // Store color on the graphics object for rendering
+    const gfx = this._remoteGfx.get(userId)!;
+    (gfx as any)._laserColor = color;
+
+    for (const p of points) {
+      arr.push({ x: p.x, y: p.y, t: now });
+    }
+    if (arr.length > this._maxPoints) {
+      arr.splice(0, arr.length - this._maxPoints);
+    }
+
+    // Ensure render loop is running
+    if (this._rafId === null) {
+      this._tick();
+    }
+  }
+
+  /** Remove a remote user's laser entirely */
+  removeRemote(userId: string): void {
+    const gfx = this._remoteGfx.get(userId);
+    if (gfx) {
+      gfx.clear();
+      gfx.destroy();
+      this._remoteGfx.delete(userId);
+    }
+    this._remotePoints.delete(userId);
+  }
+
+  /** rAF-driven render loop */
+  private _tick = (): void => {
+    this._render();
+
+    // Check if there's anything left to draw
+    const hasLocal = this._points.length > 0;
+    let hasRemote = false;
+    for (const [, pts] of this._remotePoints) {
+      if (pts.length > 0) {
+        hasRemote = true;
+        break;
+      }
+    }
+
+    if (hasLocal || hasRemote || this._active) {
+      this._rafId = requestAnimationFrame(this._tick);
+    } else {
+      this._rafId = null;
+    }
+  };
+
+  private _render(): void {
+    const now = performance.now();
+    const scale = this._viewport.scale.x || 1;
+    const lineWidth = 3 / scale;
+
+    // --- Local laser ---
+    this._prunePoints(this._points, now);
+    this._drawTrail(this._gfx, this._points, this._color, lineWidth, now);
+
+    // --- Remote lasers ---
+    for (const [userId, pts] of this._remotePoints) {
+      this._prunePoints(pts, now);
+      const gfx = this._remoteGfx.get(userId);
+      if (!gfx) continue;
+      const color = (gfx as any)._laserColor ?? 0xff4444;
+      this._drawTrail(gfx, pts, color, lineWidth, now);
+
+      // Clean up empty remote lasers
+      if (pts.length === 0) {
+        gfx.clear();
+        // Don't destroy — they may send more points
+      }
+    }
+  }
+
+  private _prunePoints(points: LaserPoint[], now: number): void {
+    while (points.length > 0 && now - points[0].t > this._fadeMs) {
+      points.shift();
+    }
+  }
+
+  private _drawTrail(
+    gfx: Graphics,
+    points: LaserPoint[],
+    color: number,
+    lineWidth: number,
+    now: number,
+  ): void {
+    gfx.clear();
+    if (points.length < 2) return;
+
+    for (let i = 1; i < points.length; i++) {
+      const p0 = points[i - 1];
+      const p1 = points[i];
+      const age = now - p1.t;
+      const alpha = Math.max(0, 1 - age / this._fadeMs);
+      if (alpha <= 0) continue;
+
+      gfx.setStrokeStyle({ width: lineWidth, color, alpha, cap: 'round', join: 'round' });
+      gfx.moveTo(p0.x, p0.y);
+      gfx.lineTo(p1.x, p1.y);
+      gfx.stroke();
+    }
+  }
+
+  /** Clean up all resources */
+  destroy(): void {
+    if (this._rafId !== null) {
+      cancelAnimationFrame(this._rafId);
+      this._rafId = null;
+    }
+    this._active = false;
+    this._points.length = 0;
+
+    this._gfx.clear();
+    this._gfx.destroy();
+
+    for (const [, gfx] of this._remoteGfx) {
+      gfx.clear();
+      gfx.destroy();
+    }
+    this._remoteGfx.clear();
+    this._remotePoints.clear();
+  }
+}

frontend/src/canvas/PixiCanvas.tsx

@@ -12,10 +12,11 @@ import {
   useImperativeHandle,
   useRef,
   useCallback,
+  useState,
 } from 'react';
 import { Application } from 'pixi.js';
 import { Viewport } from 'pixi-viewport';
-import { SceneManager } from './SceneManager';
+import { SceneManager, getItemWorldBounds } from './SceneManager';
 import { TextureManager } from './TextureManager';
 import { SpringManager } from './spring';
 import { convertFabricToV2 } from './scene-format';
@@ -28,13 +29,14 @@ import type { SceneData } from './scene-format';
 export interface PixiCanvasHandle {
   getViewport: () => Viewport | null;
   getScene: () => SceneManager | null;
+  getApp: () => Application | null;
   fitAll: () => void;
   getZoom: () => number;
   setZoom: (zoom: number) => void;
 }
 
 export interface PixiCanvasProps {
-  canvasState?: string | null;
+  canvasState?: string | object | null;
   currentTool: string;
   boardId?: string;
   onChange?: () => void;
@@ -99,6 +101,7 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
     const initialLoadDone = useRef(false);
     const spaceHeld = useRef(false);
     const onChangeRef = useRef(onChange);
+    const [pixiReady, setPixiReady] = useState(false);
 
     // Keep onChange ref current without re-running effects
     onChangeRef.current = onChange;
@@ -121,6 +124,7 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
           antialias: true,
           autoDensity: true,
           resolution: window.devicePixelRatio,
+          preserveDrawingBuffer: true,
         });
 
         if (destroyed) {
@@ -160,7 +164,7 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
           springs.tick(ticker.deltaMS / 1000);
         });
 
-        // -- Culling + LOD ticker (runs every 200ms, not every frame) ------
+        // -- Visibility culling ticker (runs every 200ms, not every frame) --
 
         let lastCullCheck = 0;
         app.ticker.add((ticker) => {
@@ -168,29 +172,18 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
           if (lastCullCheck < 200) return;
           lastCullCheck = 0;
 
-          const zoom = viewport.scale.x;
           const bounds = viewport.getVisibleBounds();
           const margin = 200;
 
           for (const item of scene.getAllItems()) {
-            const d = item.displayObject;
+            if (item.type === 'video' && 'onVisibilityChange' in item.displayObject) {
-            const ib = d.getBounds();
+              const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
-            const inView =
+              const inView =
-              ib.x + ib.width > bounds.x - margin &&
+                ix + iw > bounds.x - margin &&
-              ib.x < bounds.x + bounds.width + margin &&
+                ix < bounds.x + bounds.width + margin &&
-              ib.y + ib.height > bounds.y - margin &&
+                iy + ih > bounds.y - margin &&
-              ib.y < bounds.y + bounds.height + margin;
+                iy < bounds.y + bounds.height + margin;
-
+              (item.displayObject as any).onVisibilityChange(inView);
-            if (item.type === 'image' && 'updateLOD' in d) {
-              if (inView) {
-                (d as any).updateLOD(zoom);
-                d.visible = true;
-              } else {
-                d.visible = false;
-              }
-            }
-            if (item.type === 'video' && 'onVisibilityChange' in d) {
-              (d as any).onVisibilityChange(inView);
             }
           }
         });
@@ -230,6 +223,18 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
 
         // Store observer for cleanup
         (container as any).__pixiRO = ro;
+
+        // Signal that PixiJS is ready for scene loading
+        setPixiReady(true);
+
+        // -- Prevent Ctrl+wheel browser zoom on canvas -----------------------
+        const preventBrowserZoom = (e: WheelEvent) => {
+          if (e.ctrlKey) {
+            e.preventDefault();
+          }
+        };
+        container.addEventListener('wheel', preventBrowserZoom, { passive: false });
+        (container as any).__pixiWheelHandler = preventBrowserZoom;
       })();
 
       // -- Cleanup ---------------------------------------------------------
@@ -243,6 +248,12 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
           delete (container as any).__pixiRO;
         }
 
+        const wheelHandler = (container as any).__pixiWheelHandler;
+        if (wheelHandler) {
+          container.removeEventListener('wheel', wheelHandler);
+          delete (container as any).__pixiWheelHandler;
+        }
+
         textures.clear();
 
         if (appRef.current) {
@@ -263,11 +274,16 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
       if (initialLoadDone.current) return;
       if (!canvasState || !sceneRef.current) return;
 
+      // canvasState may be a JSON string or already-parsed object
       let parsed: any;
-      try {
+      if (typeof canvasState === 'string') {
-        parsed = JSON.parse(canvasState);
+        try {
-      } catch {
+          parsed = JSON.parse(canvasState);
-        return;
+        } catch {
+          return;
+        }
+      } else {
+        parsed = canvasState;
       }
 
       let sceneData: SceneData;
@@ -279,7 +295,7 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
 
       initialLoadDone.current = true;
       sceneRef.current.loadScene(sceneData, false);
-    }, [canvasState]);
+    }, [canvasState, pixiReady]);
 
     // ── Space key for pan mode ────────────────────────────────────────
 
@@ -337,12 +353,11 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
       let maxY = -Infinity;
 
       for (const item of items) {
-        const obj = item.displayObject;
+        const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
-        const bounds = obj.getBounds();
+        if (ix < minX) minX = ix;
-        if (bounds.x < minX) minX = bounds.x;
+        if (iy < minY) minY = iy;
-        if (bounds.y < minY) minY = bounds.y;
+        if (ix + iw > maxX) maxX = ix + iw;
-        if (bounds.x + bounds.width > maxX) maxX = bounds.x + bounds.width;
+        if (iy + ih > maxY) maxY = iy + ih;
-        if (bounds.y + bounds.height > maxY) maxY = bounds.y + bounds.height;
       }
 
       const padding = 40;
@@ -368,6 +383,7 @@ const PixiCanvas = forwardRef<PixiCanvasHandle, PixiCanvasProps>(
       () => ({
         getViewport: () => viewportRef.current,
         getScene: () => sceneRef.current,
+        getApp: () => appRef.current,
         fitAll,
         getZoom: () => viewportRef.current?.scale.x ?? 1,
         setZoom: (zoom: number) => {

frontend/src/canvas/PresenceOverlay.ts

@@ -0,0 +1,172 @@
+/**
+ * PresenceOverlay — renders colored selection borders for remote users.
+ *
+ * When another user selects items on the collaborative whiteboard, this overlay
+ * draws thin colored outlines around those items on the local screen, with a
+ * name-label pill above the first selected item.
+ */
+
+import { Container, Graphics, Text, TextStyle } from 'pixi.js';
+import type { Viewport } from 'pixi-viewport';
+import type { SceneManager } from './SceneManager';
+import { getItemWorldBounds } from './SceneManager';
+
+interface RemoteSelection {
+  userId: string;
+  displayName: string;
+  color: number; // hex color, e.g. 0xff6600
+  itemIds: string[];
+}
+
+export class PresenceOverlay {
+  private _viewport: Viewport;
+  private _scene: SceneManager;
+  private _container: Container;
+  private _selections: Map<string, RemoteSelection> = new Map();
+  private _graphics: Map<string, Graphics> = new Map(); // per-user graphics
+  private _labels: Map<string, Text> = new Map(); // per-user name label
+  private _rafId: number | null = null;
+
+  constructor(viewport: Viewport, scene: SceneManager) {
+    this._viewport = viewport;
+    this._scene = scene;
+    this._container = new Container();
+    this._container.label = '__presence_overlay';
+    this._container.eventMode = 'none';
+    this._container.interactiveChildren = false;
+    viewport.addChild(this._container);
+  }
+
+  /** Update a remote user's selection. Empty array = deselected. */
+  updateSelection(userId: string, displayName: string, color: number, itemIds: string[]): void {
+    if (itemIds.length === 0) {
+      this._selections.delete(userId);
+      this._cleanupUser(userId);
+    } else {
+      this._selections.set(userId, { userId, displayName, color, itemIds });
+    }
+    this._scheduleRedraw();
+  }
+
+  /** Remove a user entirely (they disconnected / left). */
+  removeUser(userId: string): void {
+    this._selections.delete(userId);
+    this._cleanupUser(userId);
+  }
+
+  private _cleanupUser(userId: string): void {
+    const gfx = this._graphics.get(userId);
+    if (gfx) {
+      gfx.destroy();
+      this._graphics.delete(userId);
+    }
+    const label = this._labels.get(userId);
+    if (label) {
+      label.destroy();
+      this._labels.delete(userId);
+    }
+  }
+
+  private _scheduleRedraw(): void {
+    if (this._rafId !== null) return;
+    this._rafId = requestAnimationFrame(() => {
+      this._rafId = null;
+      this._redraw();
+    });
+  }
+
+  private _redraw(): void {
+    const zoom = this._viewport.scale.x;
+
+    for (const [userId, sel] of this._selections) {
+      // Get or create graphics for this user
+      let gfx = this._graphics.get(userId);
+      if (!gfx) {
+        gfx = new Graphics();
+        gfx.label = `__presence_${userId}`;
+        this._container.addChild(gfx);
+        this._graphics.set(userId, gfx);
+      }
+      gfx.clear();
+
+      // Get or create label
+      let label = this._labels.get(userId);
+      if (!label) {
+        label = new Text({
+          text: sel.displayName,
+          style: new TextStyle({
+            fontSize: 10,
+            fontFamily: 'system-ui, sans-serif',
+            fill: '#ffffff',
+            fontWeight: '600',
+          }),
+        });
+        label.label = `__presence_label_${userId}`;
+        this._container.addChild(label);
+        this._labels.set(userId, label);
+      }
+      label.text = sel.displayName;
+      label.visible = false; // hide until we know where to place it
+      label.scale.set(1 / zoom); // fixed screen-space size
+
+      // Draw border around each selected item, track first bounds for label
+      let firstBounds: { x: number; y: number; w: number; h: number } | null = null;
+
+      for (const itemId of sel.itemIds) {
+        const item = this._scene.getById(itemId);
+        if (!item) continue;
+
+        const b = getItemWorldBounds(item);
+
+        const pad = 2 / zoom;
+        gfx.rect(b.x - pad, b.y - pad, b.w + pad * 2, b.h + pad * 2);
+        gfx.stroke({ color: sel.color, width: 1.5 / zoom, alpha: 0.7 });
+
+        if (!firstBounds) firstBounds = b;
+      }
+
+      // Position name-label pill above the first selected item
+      if (firstBounds) {
+        // Draw background pill first so text renders on top
+        const labelOffsetY = 16 / zoom;
+        const px = 3 / zoom;
+
+        // We need label dimensions — make it visible and measure
+        label.visible = true;
+        label.position.set(firstBounds.x, firstBounds.y - labelOffsetY);
+
+        const lw = label.width;
+        const lh = label.height;
+
+        gfx.roundRect(
+          firstBounds.x - px,
+          firstBounds.y - labelOffsetY - px / 2,
+          lw + px * 2,
+          lh + px,
+          2 / zoom,
+        );
+        gfx.fill({ color: sel.color, alpha: 0.85 });
+      }
+    }
+
+    // Clean up graphics/labels for users no longer in _selections
+    for (const userId of this._graphics.keys()) {
+      if (!this._selections.has(userId)) {
+        this._cleanupUser(userId);
+      }
+    }
+  }
+
+  /** Call when items may have moved to keep borders in sync. */
+  refresh(): void {
+    if (this._selections.size > 0) this._redraw();
+  }
+
+  destroy(): void {
+    if (this._rafId !== null) cancelAnimationFrame(this._rafId);
+    this._container.destroy({ children: true });
+    this._graphics.clear();
+    this._labels.clear();
+    this._selections.clear();
+  }
+}

frontend/src/canvas/SceneManager.ts

@@ -5,16 +5,22 @@
  * and spring-animated add/remove operations.
  */
 
-import { Container, Sprite, Texture, Graphics, Text, TextStyle } from 'pixi.js';
+import { Container, Graphics, Text, TextStyle } from 'pixi.js';
 import type { Viewport } from 'pixi-viewport';
-import { TextureManager, LODTier } from './TextureManager';
+import { TextureManager } from './TextureManager';
+import { ImageSprite } from './sprites/ImageSprite';
+import { VideoSprite } from './sprites/VideoSprite';
+import { DrawingSprite } from './sprites/DrawingSprite';
+import { FrameSprite } from './sprites/FrameSprite';
 import { SpringManager, Spring, PRESETS } from './spring';
+import { reparentGroupChildren } from './grouping';
 import type {
   SceneData,
   AnySceneObject,
   ImageObject,
   VideoObject,
   TextObject,
+  DrawingObject,
   GroupObject,
   SceneObject,
 } from './scene-format';
@@ -25,11 +31,106 @@ import type {
 
 export interface SceneItem {
   id: string;
-  type: 'image' | 'video' | 'text' | 'group';
+  type: 'image' | 'video' | 'text' | 'drawing' | 'group';
   displayObject: Container;
   data: AnySceneObject;
 }
 
+/** Set of child IDs that belong to a group — rebuilt when groups change. */
+let _groupChildIds: Set<string> | null = null;
+
+/** Rebuild the set of all group-child IDs. Call after group add/remove/load. */
+export function rebuildGroupChildSet(scene: SceneManager): void {
+  _groupChildIds = new Set<string>();
+  for (const item of scene.items.values()) {
+    if (item.data.type !== 'group') continue;
+    const gd = item.data as GroupObject;
+    for (const cid of gd.children) _groupChildIds.add(cid);
+  }
+}
+
+/** Returns true if the item is a child of a group (not independently selectable). */
+export function isGroupChild(id: string): boolean {
+  return _groupChildIds?.has(id) ?? false;
+}
+
+/** Single source of truth for an item's world-space bounding rect.
+ *  Uses data.sx/sy (not obj.scale which may be mid-animation).
+ *  For groups: computes the union of children bounds (w/h on group data may be 0).
+ *  For group children: converts local coords to world using parent group transforms. */
+export function getItemWorldBounds(item: SceneItem): { x: number; y: number; w: number; h: number } {
+  if (item.data.type === 'group') {
+    return _getGroupWorldBounds(item);
+  }
+
+  // If this item is a child of a group, convert local → world
+  const parent = item.displayObject.parent;
+  if (parent && parent.label && _groupChildIds?.has(item.id)) {
+    const px = parent.position.x;
+    const py = parent.position.y;
+    const psx = parent.scale.x;
+    const psy = parent.scale.y;
+    return {
+      x: px + item.data.x * psx,
+      y: py + item.data.y * psy,
+      w: item.data.w * Math.abs(item.data.sx * psx),
+      h: item.data.h * Math.abs(item.data.sy * psy),
+    };
+  }
+
+  return {
+    x: item.data.x,
+    y: item.data.y,
+    w: item.data.w * Math.abs(item.data.sx),
+    h: item.data.h * Math.abs(item.data.sy),
+  };
+}
+
+/**
+ * Compute group bounds from its data.w/h (set during grouping) or fall back
+ * to stored children data. Children store LOCAL x/y relative to group.
+ */
+function _getGroupWorldBounds(item: SceneItem): { x: number; y: number; w: number; h: number } {
+  const groupX = item.data.x;
+  const groupY = item.data.y;
+  const groupW = item.data.w;
+  const groupH = item.data.h;
+
+  // If group has valid w/h (set during creation), apply scale just like regular items
+  if (groupW > 0 && groupH > 0) {
+    return {
+      x: groupX,
+      y: groupY,
+      w: groupW * Math.abs(item.data.sx),
+      h: groupH * Math.abs(item.data.sy),
+    };
+  }
+
+  // Fallback: shouldn't happen, but compute from children display objects
+  const container = item.displayObject;
+  if (container.children.length === 0) {
+    return { x: groupX, y: groupY, w: 0, h: 0 };
+  }
+
+  let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+  for (const child of container.children) {
+    const cx = child.x;
+    const cy = child.y;
+    // Approximate child size from its local bounds
+    const lb = child.getLocalBounds();
+    const cw = lb.width;
+    const ch = lb.height;
+    minX = Math.min(minX, cx);
+    minY = Math.min(minY, cy);
+    maxX = Math.max(maxX, cx + cw);
+    maxY = Math.max(maxY, cy + ch);
+  }
+
+  if (!isFinite(minX)) return { x: groupX, y: groupY, w: 0, h: 0 };
+  // Children positions are local to group, so offset by group world position
+  return { x: groupX + minX, y: groupY + minY, w: maxX - minX, h: maxY - minY };
+}
+
 // ---------------------------------------------------------------------------
 // SceneManager
 // ---------------------------------------------------------------------------
@@ -41,6 +142,7 @@ export class SceneManager {
   readonly springs: SpringManager;
 
   private _onChange: (() => void) | null = null;
+  private _onItemDimensionsChanged: ((itemId: string) => void) | null = null;
   private _zCounter: number = 0;
 
   constructor(viewport: Viewport, textures: TextureManager, springs: SpringManager) {
@@ -55,6 +157,10 @@ export class SceneManager {
     this._onChange = fn;
   }
 
+  set onItemDimensionsChanged(fn: ((itemId: string) => void) | null) {
+    this._onItemDimensionsChanged = fn;
+  }
+
   get onChange(): (() => void) | null {
     return this._onChange;
   }
@@ -98,6 +204,21 @@ export class SceneManager {
     }
     for (const id of toRemove) {
       const item = this.items.get(id)!;
+
+      // If removing a group, reparent its PixiJS children to viewport first
+      // so they survive the container destruction (they may still be in the
+      // incoming set as ungrouped top-level items).
+      if (item.data.type === 'group') {
+        const container = item.displayObject;
+        // Reparent actual scene children (skip internal frame bg/label)
+        const toReparent = container.children.filter(
+          (c) => !c.label?.startsWith('__frame_'),
+        );
+        for (const child of toReparent) {
+          this.viewport.addChild(child);
+        }
+      }
+
       item.displayObject.destroy({ children: true });
       this.items.delete(id);
     }
@@ -121,7 +242,11 @@ export class SceneManager {
 
     await Promise.all(loadPromises);
 
-    // 4. Apply z-ordering
+    // 4. Reparent group children into their group containers
+    reparentGroupChildren(this);
+    rebuildGroupChildSet(this);
+
+    // 5. Apply z-ordering
     this._applyZOrder();
 
     this._onChange?.();
@@ -136,31 +261,18 @@ export class SceneManager {
     switch (data.type) {
       case 'image': {
         const imgData = data as ImageObject;
-        const sprite = new Sprite(Texture.EMPTY);
+        displayObject = new ImageSprite(imgData.asset, imgData.w, imgData.h, this.textures);
-        sprite.width = imgData.w;
-        sprite.height = imgData.h;
-
-        // Load texture asynchronously at appropriate LOD
-        const zoom = this.viewport.scale.x;
-        const tier = this.textures.tierForZoom(zoom);
-        this.textures.load(imgData.asset, tier).then((tex) => {
-          if (!sprite.destroyed) {
-            sprite.texture = tex;
-            sprite.width = imgData.w;
-            sprite.height = imgData.h;
-          }
-        });
-
-        displayObject = sprite;
         break;
       }
 
       case 'video': {
         const vidData = data as VideoObject;
-        const gfx = new Graphics();
+        const videoUrl = this.textures.urlForAsset(vidData.asset);
-        gfx.rect(0, 0, vidData.w, vidData.h);
+        const videoSprite = new VideoSprite(vidData.asset, vidData.w, vidData.h, videoUrl);
-        gfx.fill(0x333333);
+        // Auto-correct dimensions when video metadata loads
-        displayObject = gfx;
+        // NOTE: callback must update item.data (the stored copy), not the original `data` param.
+        // We wire this after the item is created below (see post-creation video wiring).
+        displayObject = videoSprite;
         break;
       }
 
@@ -175,8 +287,15 @@ export class SceneManager {
         break;
       }
 
+      case 'drawing': {
+        const drawData = data as DrawingObject;
+        displayObject = new DrawingSprite(drawData.points, drawData.color, drawData.strokeWidth);
+        break;
+      }
+
       case 'group': {
-        displayObject = new Container();
+        const gd = data as GroupObject;
+        displayObject = new FrameSprite(gd.w, gd.h, gd.bgColor, gd.label, gd.padding);
         break;
       }
 
@@ -206,23 +325,52 @@ export class SceneManager {
 
     this.items.set(data.id, item);
 
-    // Animate entrance: spring scale from 0 → 1.05 → 1.0 with fade-in
+    // Wire video dimension auto-correction to the STORED item.data (not the original param)
+    if (data.type === 'video' && displayObject instanceof VideoSprite) {
+      displayObject.onDimensionsKnown = (realW, realH) => {
+        item.data.w = realW;
+        item.data.h = realH;
+        this._onChange?.();
+        this._onItemDimensionsChanged?.(item.id);
+      };
+    }
+
+    // Animate entrance: spring scale from center 0 → 1.05 → 1.0 with fade-in
     if (animate) {
       displayObject.scale.set(0, 0);
       displayObject.alpha = 0;
 
+      // Scale from center by adjusting position to keep center point fixed
+      const halfW = data.w * data.sx / 2;
+      const halfH = data.h * data.sy / 2;
+      const finalX = data.x;
+      const finalY = data.y;
+
       const scaleSpring = new Spring(0, 1.05, PRESETS.bounce);
       scaleSpring.onUpdate = (v) => {
         if (!displayObject.destroyed) {
           displayObject.scale.set(v * data.sx, v * data.sy);
+          displayObject.position.set(
+            finalX + halfW * (1 - v),
+            finalY + halfH * (1 - v),
+          );
         }
       };
       scaleSpring.onComplete = () => {
-        // Second spring: 1.05 → 1.0
         const settleSpring = new Spring(1.05, 1.0, PRESETS.snappy);
         settleSpring.onUpdate = (v) => {
           if (!displayObject.destroyed) {
             displayObject.scale.set(v * data.sx, v * data.sy);
+            displayObject.position.set(
+              finalX + halfW * (1 - v),
+              finalY + halfH * (1 - v),
+            );
+          }
+        };
+        settleSpring.onComplete = () => {
+          if (!displayObject.destroyed) {
+            displayObject.position.set(finalX, finalY);
+            displayObject.scale.set(data.sx, data.sy);
           }
         };
         this.springs.add(settleSpring);
@@ -252,6 +400,21 @@ export class SceneManager {
     obj.visible = data.visible;
     obj.eventMode = data.locked ? 'none' : 'static';
 
+    // Type-specific updates
+    if (data.type === 'drawing' && obj instanceof DrawingSprite) {
+      const drawData = data as DrawingObject;
+      obj.setPoints(drawData.points);
+    }
+    if (data.type === 'text' && obj instanceof Text) {
+      const txtData = data as TextObject;
+      obj.text = txtData.text;
+      obj.style.fontSize = txtData.fontSize;
+      obj.style.fill = txtData.fill;
+    }
+    if (data.type === 'group' && obj instanceof FrameSprite) {
+      obj.updateFromData(data as GroupObject);
+    }
+
     // Update stored data
     item.data = { ...data };
     item.type = data.type;
@@ -259,16 +422,47 @@ export class SceneManager {
 
   // -- Z-Ordering ----------------------------------------------------------
 
-  /** Sort items by z and reorder children in the viewport. */
+  /** Sort items by z and reorder children in both viewport and group containers. */
   _applyZOrder(): void {
     const sorted = Array.from(this.items.values()).sort(
       (a, b) => a.data.z - b.data.z,
     );
 
-    for (let i = 0; i < sorted.length; i++) {
+    // Reorder top-level items in the viewport
-      const child = sorted[i].displayObject;
+    let vpIndex = 0;
+    for (const item of sorted) {
+      const child = item.displayObject;
       if (child.parent === this.viewport) {
-        this.viewport.setChildIndex(child, i);
+        // Clamp index to valid range (selection overlay etc. may also be viewport children)
+        const maxIdx = this.viewport.children.length - 1;
+        const targetIdx = Math.min(vpIndex, maxIdx);
+        if (this.viewport.getChildIndex(child) !== targetIdx) {
+          this.viewport.setChildIndex(child, targetIdx);
+        }
+        vpIndex++;
+      }
+    }
+
+    // Reorder children within each group container
+    for (const item of sorted) {
+      if (item.data.type !== 'group') continue;
+      const groupData = item.data as GroupObject;
+      const container = item.displayObject;
+      // Sort children by their z value within the group
+      const childItems = groupData.children
+        .map((id) => this.items.get(id))
+        .filter((c): c is SceneItem => !!c)
+        .sort((a, b) => a.data.z - b.data.z);
+
+      for (let i = 0; i < childItems.length; i++) {
+        const child = childItems[i].displayObject;
+        if (child.parent === container) {
+          const maxIdx = container.children.length - 1;
+          const targetIdx = Math.min(i, maxIdx);
+          if (container.getChildIndex(child) !== targetIdx) {
+            container.setChildIndex(child, targetIdx);
+          }
+        }
       }
     }
   }
@@ -283,13 +477,27 @@ export class SceneManager {
     return Array.from(this.items.values());
   }
 
+  /** Get only top-level items (excludes group children). Used for selection/hit testing. */
+  getTopLevelItems(): SceneItem[] {
+    return Array.from(this.items.values()).filter((item) => !isGroupChild(item.id));
+  }
+
   // -- Remove Item ---------------------------------------------------------
 
-  /** Remove an item, optionally animating scale→0.8 + fade out before destroy. */
+  /** Remove an item, optionally animating scale→0.8 + fade out before destroy.
+   *  If item is a group, recursively removes all children from the items map. */
   removeItem(id: string, animate = true): void {
     const item = this.items.get(id);
     if (!item) return;
 
+    // If this is a group, remove children from the items map first
+    if (item.data.type === 'group') {
+      const groupData = item.data as import('./scene-format').GroupObject;
+      for (const childId of groupData.children) {
+        this.items.delete(childId);
+      }
+    }
+
     if (!animate) {
       item.displayObject.destroy({ children: true });
       this.items.delete(id);
@@ -302,10 +510,20 @@ export class SceneManager {
     // Remove from map immediately to prevent double-remove
     this.items.delete(id);
 
+    // Scale toward center on removal
+    const halfW = item.data.w * item.data.sx / 2;
+    const halfH = item.data.h * item.data.sy / 2;
+    const startX = item.data.x;
+    const startY = item.data.y;
+
     const scaleSpring = new Spring(1.0, 0.8, PRESETS.snappy);
     scaleSpring.onUpdate = (v) => {
       if (!obj.destroyed) {
-        obj.scale.set(v * (item.data.sx), v * (item.data.sy));
+        obj.scale.set(v * item.data.sx, v * item.data.sy);
+        obj.position.set(
+          startX + halfW * (1 - v),
+          startY + halfH * (1 - v),
+        );
       }
     };
     this.springs.add(scaleSpring);
@@ -371,6 +589,41 @@ export class SceneManager {
     return this.items.get(data.id)!;
   }
 
+  /** Create a VideoObject from an upload and add it to the scene with animation. */
+  addVideoFromUpload(
+    assetKey: string,
+    w: number,
+    h: number,
+    x: number,
+    y: number,
+  ): SceneItem {
+    const data: VideoObject = {
+      id: crypto.randomUUID(),
+      type: 'video',
+      x,
+      y,
+      w,
+      h,
+      sx: 1,
+      sy: 1,
+      angle: 0,
+      z: this.nextZ(),
+      opacity: 1,
+      locked: false,
+      name: '',
+      visible: true,
+      asset: assetKey,
+      muted: true,
+      loop: true,
+    };
+
+    this._createItem(data, true);
+    this._applyZOrder();
+    this._onChange?.();
+
+    return this.items.get(data.id)!;
+  }
+
   // -- Group / Ungroup with Spring Animation --------------------------------
 
   /**

frontend/src/canvas/SelectionManager.ts

@@ -7,8 +7,9 @@
 
 import { Container, Graphics, FederatedPointerEvent } from 'pixi.js';
 import type { Viewport } from 'pixi-viewport';
-import { SceneManager, SceneItem, getItemWorldBounds, isGroupChild } from './SceneManager';
+import { SceneManager, SceneItem, getItemWorldBounds } from './SceneManager';
 import { TransformBox } from './TransformBox';
+import { SnapGuides } from './SnapGuides';
 import { ImageSprite } from './sprites/ImageSprite';
 import { VideoSprite } from './sprites/VideoSprite';
 
@@ -31,6 +32,7 @@ const DRAG_THRESHOLD = 5;        // px in screen space before object drag activa
 export class SelectionManager {
   readonly selectedIds: Set<string> = new Set();
   readonly transformBox: TransformBox;
+  private _snapGuides: SnapGuides;
 
   private _viewport: Viewport;
   private _scene: SceneManager;
@@ -62,6 +64,8 @@ export class SelectionManager {
 
   private _enabled = true;
 
+  get snapGuides(): SnapGuides { return this._snapGuides; }
+
   constructor(viewport: Viewport, scene: SceneManager) {
     this._viewport = viewport;
     this._scene = scene;
@@ -81,6 +85,9 @@ export class SelectionManager {
     this.transformBox.setViewport(viewport);
     this._overlay.addChild(this.transformBox);
 
+    // Snap guides
+    this._snapGuides = new SnapGuides(scene, this._overlay);
+
     // Bind events on viewport
     viewport.on('pointerdown', this._onPointerDown, this);
     viewport.on('globalpointermove', this._onPointerMove, this);
@@ -229,17 +236,31 @@ export class SelectionManager {
 
         // Lift shadow + spring scale on all selected image sprites
         this._applyLift();
+
+        // Begin snap guide session
+        this._snapGuides.beginSession(this.selectedIds);
       }
 
       if (this._objectDragging) {
         const currentWorld = this._viewport.toWorld(e.global.x, e.global.y);
-        const ddx = currentWorld.x - this._lastDragWorldX;
+        let ddx = currentWorld.x - this._lastDragWorldX;
-        const ddy = currentWorld.y - this._lastDragWorldY;
+        let ddy = currentWorld.y - this._lastDragWorldY;
         this._lastDragWorldX = currentWorld.x;
         this._lastDragWorldY = currentWorld.y;
 
-        // Move all selected items by delta and broadcast transforms
+        // Compute combined bounds of selected items after applying delta
         const selected = this.getSelectedItems();
+        const prospective = this._getSelectionBounds(selected);
+        prospective.x += ddx;
+        prospective.y += ddy;
+
+        // Snap to alignment guides
+        const snap = this._snapGuides.computeSnap(prospective, this._viewport);
+        ddx += snap.dx;
+        ddy += snap.dy;
+        this._snapGuides.drawGuides(snap.guides, this._viewport);
+
+        // Move all selected items by corrected delta and broadcast transforms
         for (const item of selected) {
           item.displayObject.x += ddx;
           item.displayObject.y += ddy;
@@ -274,6 +295,7 @@ export class SelectionManager {
     if (this._objectDragging) {
       // End object drag — drop shadow + spring scale back
       this._applyDrop();
+      this._snapGuides.endSession();
       this._objectDragging = false;
 
       // Resume viewport drag
@@ -390,6 +412,26 @@ export class SelectionManager {
     this._emitChange();
   }
 
+  // -- Selection Bounds Helper -----------------------------------------------
+
+  /** Compute the combined world bounding rect of the given items. */
+  private _getSelectionBounds(items: SceneItem[]): { x: number; y: number; w: number; h: number } {
+    let minX = Infinity;
+    let minY = Infinity;
+    let maxX = -Infinity;
+    let maxY = -Infinity;
+
+    for (const item of items) {
+      const { x, y, w, h } = getItemWorldBounds(item);
+      if (x < minX) minX = x;
+      if (y < minY) minY = y;
+      if (x + w > maxX) maxX = x + w;
+      if (y + h > maxY) maxY = y + h;
+    }
+
+    return { x: minX, y: minY, w: maxX - minX, h: maxY - minY };
+  }
+
   // -- Change Notification --------------------------------------------------
 
   private _emitChange(): void {

frontend/src/canvas/SnapGuides.ts

@@ -0,0 +1,192 @@
+/**
+ * SnapGuides — alignment snap guides for drag/resize operations (like Figma).
+ *
+ * Shows thin magenta guide lines when edges or centers of dragged items
+ * align with other items on the canvas, and returns snap corrections.
+ */
+
+import { Container, Graphics } from 'pixi.js';
+import type { Viewport } from 'pixi-viewport';
+import { SceneManager, getItemWorldBounds } from './SceneManager';
+
+// ---------------------------------------------------------------------------
+// Constants
+// ---------------------------------------------------------------------------
+
+const SNAP_THRESHOLD = 4; // pixels in screen space (subtle, not aggressive)
+const GUIDE_COLOR = 0xff4081;
+const GUIDE_PADDING = 20; // world-space extension beyond bounds
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+export interface SnapEdge {
+  axis: 'x' | 'y';
+  value: number;
+  min: number;
+  max: number;
+}
+
+export interface SnapResult {
+  dx: number;
+  dy: number;
+  guides: SnapEdge[];
+}
+
+// ---------------------------------------------------------------------------
+// SnapGuides
+// ---------------------------------------------------------------------------
+
+export class SnapGuides {
+  private _scene: SceneManager;
+  private _gfx: Graphics;
+
+  /** Cached candidate edges from non-selected items. */
+  private _candidatesX: { value: number; min: number; max: number }[] = [];
+  private _candidatesY: { value: number; min: number; max: number }[] = [];
+
+  constructor(scene: SceneManager, parent: Container) {
+    this._scene = scene;
+    this._gfx = new Graphics();
+    this._gfx.label = '__snap_guides';
+    parent.addChild(this._gfx);
+  }
+
+  // -----------------------------------------------------------------------
+  // Session management
+  // -----------------------------------------------------------------------
+
+  /** Cache candidate edges from all visible, unlocked, non-selected top-level items. */
+  beginSession(excludeIds: Set<string>): void {
+    this._candidatesX = [];
+    this._candidatesY = [];
+
+    for (const item of this._scene.getTopLevelItems()) {
+      if (excludeIds.has(item.id)) continue;
+      if (item.data.locked || !item.data.visible) continue;
+
+      const { x, y, w, h } = getItemWorldBounds(item);
+      const right = x + w;
+      const bottom = y + h;
+      const cx = x + w / 2;
+      const cy = y + h / 2;
+
+      // X-axis edges: left, center, right
+      this._candidatesX.push({ value: x, min: y, max: bottom });
+      this._candidatesX.push({ value: cx, min: y, max: bottom });
+      this._candidatesX.push({ value: right, min: y, max: bottom });
+
+      // Y-axis edges: top, center, bottom
+      this._candidatesY.push({ value: y, min: x, max: right });
+      this._candidatesY.push({ value: cy, min: x, max: right });
+      this._candidatesY.push({ value: bottom, min: x, max: right });
+    }
+  }
+
+  /** Clear cached edges and guide lines. */
+  endSession(): void {
+    this._candidatesX = [];
+    this._candidatesY = [];
+    this._gfx.clear();
+  }
+
+  // -----------------------------------------------------------------------
+  // Snap computation
+  // -----------------------------------------------------------------------
+
+  /**
+   * Compare 6 edges of the selection bounds against cached candidates.
+   * Returns correction deltas and guide lines to draw.
+   */
+  computeSnap(
+    bounds: { x: number; y: number; w: number; h: number },
+    viewport: Viewport,
+  ): SnapResult {
+    const scale = viewport.scale.x;
+    const threshold = SNAP_THRESHOLD / scale;
+
+    const { x, y, w, h } = bounds;
+    const right = x + w;
+    const bottom = y + h;
+    const cx = x + w / 2;
+    const cy = y + h / 2;
+
+    // Selection edges for each axis
+    const selEdgesX = [x, cx, right];
+    const selEdgesY = [y, cy, bottom];
+
+    // Selection extent ranges (for guide line extension)
+    const selMinY = y;
+    const selMaxY = bottom;
+    const selMinX = x;
+    const selMaxX = right;
+
+    let bestDx = Infinity;
+    let bestGuideX: SnapEdge | null = null;
+
+    // Find closest X match
+    for (const selVal of selEdgesX) {
+      for (const cand of this._candidatesX) {
+        const diff = cand.value - selVal;
+        if (Math.abs(diff) < Math.abs(bestDx)) {
+          bestDx = diff;
+          const gMin = Math.min(selMinY, cand.min) - GUIDE_PADDING;
+          const gMax = Math.max(selMaxY, cand.max) + GUIDE_PADDING;
+          bestGuideX = { axis: 'x', value: cand.value, min: gMin, max: gMax };
+        }
+      }
+    }
+
+    let bestDy = Infinity;
+    let bestGuideY: SnapEdge | null = null;
+
+    // Find closest Y match
+    for (const selVal of selEdgesY) {
+      for (const cand of this._candidatesY) {
+        const diff = cand.value - selVal;
+        if (Math.abs(diff) < Math.abs(bestDy)) {
+          bestDy = diff;
+          const gMin = Math.min(selMinX, cand.min) - GUIDE_PADDING;
+          const gMax = Math.max(selMaxX, cand.max) + GUIDE_PADDING;
+          bestGuideY = { axis: 'y', value: cand.value, min: gMin, max: gMax };
+        }
+      }
+    }
+
+    const guides: SnapEdge[] = [];
+    const dx = Math.abs(bestDx) <= threshold && bestGuideX ? bestDx : 0;
+    const dy = Math.abs(bestDy) <= threshold && bestGuideY ? bestDy : 0;
+
+    if (dx !== 0 && bestGuideX) guides.push(bestGuideX);
+    if (dy !== 0 && bestGuideY) guides.push(bestGuideY);
+
+    return { dx, dy, guides };
+  }
+
+  // -----------------------------------------------------------------------
+  // Drawing
+  // -----------------------------------------------------------------------
+
+  /** Draw guide lines; line width compensates for viewport zoom. */
+  drawGuides(guides: SnapEdge[], viewport: Viewport): void {
+    this._gfx.clear();
+
+    if (guides.length === 0) return;
+
+    const lineWidth = 1 / viewport.scale.x;
+
+    for (const g of guides) {
+      this._gfx.moveTo(
+        g.axis === 'x' ? g.value : g.min,
+        g.axis === 'x' ? g.min : g.value,
+      );
+      this._gfx.lineTo(
+        g.axis === 'x' ? g.value : g.max,
+        g.axis === 'x' ? g.max : g.value,
+      );
+    }
+
+    this._gfx.stroke({ color: GUIDE_COLOR, width: lineWidth });
+  }
+}

frontend/src/canvas/TextureManager.ts

@@ -1,67 +1,42 @@
 import { Texture, Assets } from "pixi.js";
 
-export type LODTier = "thumb" | "medium" | "full";
-
 interface TextureEntry {
   texture: Texture;
-  tier: LODTier;
   lastUsed: number;
   memoryEstimate: number;
 }
 
+/**
+ * TextureManager — GPU texture cache with LRU eviction and memory budget.
+ * No LOD tiers — PixiJS GPU handles scaling natively.
+ * Just loads the full-res image and caches it.
+ */
 export class TextureManager {
   private cache = new Map<string, TextureEntry>();
   private budget = 512 * 1024 * 1024; // 512 MB
   private currentUsage = 0;
 
-  /** Map zoom level to the appropriate LOD tier. */
+  /** Build the URL for a given asset. */
-  tierForZoom(zoom: number): LODTier {
+  urlForAsset(assetKey: string): string {
-    if (zoom < 0.3) return "thumb";
+    if (assetKey.startsWith('http') || assetKey.startsWith('/api/')) {
-    if (zoom > 1.5) return "full";
+      return assetKey;
-    return "medium";
-  }
-
-  /**
-   * Detect whether an asset key is a new LOD-format key (no extension)
-   * or an old pre-migration path (has file extension).
-   */
-  private _isLegacyAsset(assetKey: string): boolean {
-    // New LOD keys look like: boards/{boardId}/{imageId} (no extension)
-    // Old keys look like: boards/{boardId}/{imageId}.png or full URLs
-    return /\.\w{2,5}$/.test(assetKey) || assetKey.startsWith('http') || assetKey.startsWith('/api/');
-  }
-
-  /** Build the URL for a given asset + tier. */
-  urlForAsset(assetKey: string, tier: LODTier): string {
-    if (this._isLegacyAsset(assetKey)) {
-      // Legacy: load original file directly (GPU handles scaling)
-      if (assetKey.startsWith('http') || assetKey.startsWith('/api/')) {
-        return assetKey;
-      }
-      return `/api/images/${assetKey}`;
     }
-    // New LOD format: boards/{boardId}/{imageId}/thumb.webp
+    return `/api/images/${assetKey}`;
-    return `/api/images/${assetKey}/${tier}.webp`;
   }
 
   /**
-   * Load a texture for the given asset and LOD tier.
+   * Load a texture for the given asset.
-   * For legacy assets (pre-migration), loads the original file directly —
+   * Returns cached texture if available, otherwise fetches and caches.
-   * the GPU handles downscaling naturally.
+   * GPU handles all scaling — no LOD tiers needed.
-   * For new assets, loads the appropriate LOD tier with fallback.
    */
-  async load(assetKey: string, tier: LODTier): Promise<Texture> {
+  async load(assetKey: string): Promise<Texture> {
-    // For legacy assets, all tiers resolve to the same URL
+    const existing = this.cache.get(assetKey);
-    const effectiveTier = this._isLegacyAsset(assetKey) ? 'full' : tier;
-    const key = `${assetKey}:${effectiveTier}`;
-
-    const existing = this.cache.get(key);
     if (existing) {
       existing.lastUsed = performance.now();
       return existing.texture;
     }
 
-    const url = this.urlForAsset(assetKey, effectiveTier);
+    const url = this.urlForAsset(assetKey);
     let texture: Texture;
     try {
       texture = await Assets.load(url);
@@ -76,9 +51,8 @@ export class TextureManager {
 
     this.currentUsage += memoryEstimate;
 
-    this.cache.set(key, {
+    this.cache.set(assetKey, {
       texture,
-      tier,
       lastUsed: performance.now(),
       memoryEstimate,
     });
@@ -91,14 +65,13 @@ export class TextureManager {
   }
 
   /** Remove a specific texture from the cache and destroy it. */
-  unload(assetKey: string, tier: LODTier): void {
+  unload(assetKey: string): void {
-    const key = `${assetKey}:${tier}`;
+    const entry = this.cache.get(assetKey);
-    const entry = this.cache.get(key);
     if (!entry) return;
 
     this.currentUsage -= entry.memoryEstimate;
     entry.texture.destroy(true);
-    this.cache.delete(key);
+    this.cache.delete(assetKey);
   }
 
   /** Evict the least-recently-used cache entry. */

frontend/src/canvas/TransformBox.ts

@@ -6,9 +6,10 @@
  * Each handle is draggable and applies scale/rotation transforms to the items.
  */
 
-import { Container, Graphics, FederatedPointerEvent } from 'pixi.js';
+import { Container, Graphics, FederatedPointerEvent, Text, TextStyle } from 'pixi.js';
 import type { Viewport } from 'pixi-viewport';
-import type { SceneItem } from './SceneManager';
+import { type SceneItem, getItemWorldBounds } from './SceneManager';
+import type { SnapGuides } from './SnapGuides';
 
 // ---------------------------------------------------------------------------
 // Constants
@@ -19,11 +20,8 @@ const BORDER_WIDTH = 1.5;
 const HANDLE_SIZE = 8;
 const HANDLE_FILL = 0xffffff;
 const HANDLE_STROKE = 0x4a90d9;
-const ROTATE_COLOR = 0x55aa55;
-const ROTATE_OFFSET = 25;
-const ROTATE_RADIUS = 5;
 
-type HandleId = 'tl' | 'tc' | 'tr' | 'ml' | 'mr' | 'bl' | 'bc' | 'br' | 'rot';
+type HandleId = 'tl' | 'tc' | 'tr' | 'ml' | 'mr' | 'bl' | 'bc' | 'br';
 
 const HANDLE_CURSORS: Record<HandleId, string> = {
   tl: 'nwse-resize',
@@ -34,7 +32,6 @@ const HANDLE_CURSORS: Record<HandleId, string> = {
   bc: 'ns-resize',
   ml: 'ew-resize',
   mr: 'ew-resize',
-  rot: 'grab',
 };
 
 // ---------------------------------------------------------------------------
@@ -45,6 +42,7 @@ interface DragState {
   handleId: HandleId;
   startX: number;
   startY: number;
+  origBounds: { x: number; y: number; w: number; h: number };
   origTransforms: Map<string, { sx: number; sy: number; angle: number; x: number; y: number }>;
 }
 
@@ -55,11 +53,22 @@ interface DragState {
 export class TransformBox extends Container {
   private _border: Graphics;
   private _handles: Map<HandleId, Graphics> = new Map();
-  private _rotateLine: Graphics;
   private _items: SceneItem[] = [];
   private _bounds = { x: 0, y: 0, w: 0, h: 0 };
   private _drag: DragState | null = null;
   private _viewport: Viewport | null = null;
+  private _onItemTransform: ((item: SceneItem) => void) | null = null;
+  private _snapGuides: SnapGuides | null = null;
+  private _dimLabel!: Text;
+  private _dimLabelBg!: Graphics;
+
+  set onItemTransform(fn: (item: SceneItem) => void) {
+    this._onItemTransform = fn;
+  }
+
+  setSnapGuides(sg: SnapGuides): void {
+    this._snapGuides = sg;
+  }
 
   constructor() {
     super();
@@ -70,12 +79,29 @@ export class TransformBox extends Container {
     this._border = new Graphics();
     this.addChild(this._border);
 
-    // Rotate stem line
+
-    this._rotateLine = new Graphics();
+    // Dimension label (shown during resize)
-    this.addChild(this._rotateLine);
+    this._dimLabel = new Text({
+      text: '',
+      style: new TextStyle({
+        fontSize: 11,
+        fontFamily: 'system-ui, -apple-system, sans-serif',
+        fill: '#ffffff',
+        fontWeight: '500',
+      }),
+    });
+    this._dimLabel.visible = false;
+    this._dimLabel.label = '__dim_label';
+
+    this._dimLabelBg = new Graphics();
+    this._dimLabelBg.visible = false;
+    this._dimLabelBg.label = '__dim_label_bg';
+
+    this.addChild(this._dimLabelBg);
+    this.addChild(this._dimLabel);
 
     // Create all handles
-    const ids: HandleId[] = ['tl', 'tc', 'tr', 'ml', 'mr', 'bl', 'bc', 'br', 'rot'];
+    const ids: HandleId[] = ['tl', 'tc', 'tr', 'ml', 'mr', 'bl', 'bc', 'br'];
     for (const id of ids) {
       const handle = new Graphics();
       handle.eventMode = 'static';
@@ -103,23 +129,25 @@ export class TransformBox extends Container {
   update(items: SceneItem[]): void {
     this._items = items;
 
+    // Hide dimension label when not actively dragging
+    if (!this._drag) {
+      this._dimLabel.visible = false;
+      this._dimLabelBg.visible = false;
+    }
+
     if (items.length === 0) {
       this.visible = false;
       return;
     }
 
-    // Compute combined bounding rect in WORLD space using item data
+    // Compute combined bounding rect via canonical getItemWorldBounds()
-    // (not getBounds() which returns screen-space and causes offset)
     let minX = Infinity;
     let minY = Infinity;
     let maxX = -Infinity;
     let maxY = -Infinity;
 
     for (const item of items) {
-      const ix = item.data.x;
+      const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
-      const iy = item.data.y;
-      const iw = item.data.w * Math.abs(item.data.sx);
-      const ih = item.data.h * Math.abs(item.data.sy);
       if (ix < minX) minX = ix;
       if (iy < minY) minY = iy;
       if (ix + iw > maxX) maxX = ix + iw;
@@ -141,12 +169,6 @@ export class TransformBox extends Container {
     this._border.rect(x, y, w, h);
     this._border.stroke({ color: BORDER_COLOR, width: BORDER_WIDTH });
 
-    // Rotate line (from top-center up to rotate handle)
-    this._rotateLine.clear();
-    this._rotateLine.moveTo(x + w / 2, y);
-    this._rotateLine.lineTo(x + w / 2, y - ROTATE_OFFSET);
-    this._rotateLine.stroke({ color: BORDER_COLOR, width: 1 });
-
     // Position handles
     const cx = x + w / 2;
     const cy = y + h / 2;
@@ -160,25 +182,16 @@ export class TransformBox extends Container {
       bl: { px: x, py: y + h },
       bc: { px: cx, py: y + h },
       br: { px: x + w, py: y + h },
-      rot: { px: cx, py: y - ROTATE_OFFSET },
     };
 
     for (const [id, handle] of this._handles) {
       const pos = positions[id];
       handle.clear();
 
-      if (id === 'rot') {
+      const half = HANDLE_SIZE / 2;
-        // Green circle for rotation
+      handle.rect(-half, -half, HANDLE_SIZE, HANDLE_SIZE);
-        handle.circle(0, 0, ROTATE_RADIUS);
+      handle.fill(HANDLE_FILL);
-        handle.fill(ROTATE_COLOR);
+      handle.stroke({ color: HANDLE_STROKE, width: 1 });
-        handle.stroke({ color: HANDLE_STROKE, width: 1 });
-      } else {
-        // White square with blue stroke for resize
-        const half = HANDLE_SIZE / 2;
-        handle.rect(-half, -half, HANDLE_SIZE, HANDLE_SIZE);
-        handle.fill(HANDLE_FILL);
-        handle.stroke({ color: HANDLE_STROKE, width: 1 });
-      }
 
       handle.position.set(pos.px, pos.py);
     }
@@ -204,108 +217,181 @@ export class TransformBox extends Container {
       handleId: id,
       startX: e.global.x,
       startY: e.global.y,
+      origBounds: { ...this._bounds },
       origTransforms,
     };
+
+    // Begin snap session excluding current items
+    const itemIds = new Set(this._items.map((it) => it.id));
+    this._snapGuides?.beginSession(itemIds);
   }
 
   private _onHandleMove(e: FederatedPointerEvent): void {
     if (!this._drag) return;
 
-    // Convert screen-space deltas to world-space by dividing by viewport zoom
+    // Convert mouse position to world space
-    const zoom = this._viewport?.scale.x ?? 1;
+    const world = this._viewport!.toWorld(e.global.x, e.global.y);
-    const dx = (e.global.x - this._drag.startX) / zoom;
+    const { handleId, origBounds: ob, origTransforms } = this._drag;
-    const dy = (e.global.y - this._drag.startY) / zoom;
-    const { handleId, origTransforms } = this._drag;
 
-    // Use bounding box size as reference for scale sensitivity
+    // Compute scale factors: new size / original size
-    const { w: bw, h: bh } = this._bounds;
+    // Each handle has a fixed edge — the opposite side stays put
-    const refSize = Math.max(bw, bh, 100); // avoid division by tiny numbers
+    const MIN = 0.05;
+    let fx = 1; // horizontal scale multiplier
+    let fy = 1; // vertical scale multiplier
+
+    switch (handleId) {
+      // --- Corner handles (proportional) ---
+      case 'br': {
+        // Fixed edge: top-left. New size = mouse - top-left.
+        fx = Math.max(MIN, (world.x - ob.x) / ob.w);
+        fy = Math.max(MIN, (world.y - ob.y) / ob.h);
+        // Proportional: use average
+        const f = (fx + fy) / 2;
+        fx = f; fy = f;
+        break;
+      }
+      case 'tl': {
+        // Fixed edge: bottom-right
+        const right = ob.x + ob.w;
+        const bottom = ob.y + ob.h;
+        fx = Math.max(MIN, (right - world.x) / ob.w);
+        fy = Math.max(MIN, (bottom - world.y) / ob.h);
+        const f = (fx + fy) / 2;
+        fx = f; fy = f;
+        break;
+      }
+      case 'tr': {
+        // Fixed edge: bottom-left
+        const bottom = ob.y + ob.h;
+        fx = Math.max(MIN, (world.x - ob.x) / ob.w);
+        fy = Math.max(MIN, (bottom - world.y) / ob.h);
+        const f = (fx + fy) / 2;
+        fx = f; fy = f;
+        break;
+      }
+      case 'bl': {
+        // Fixed edge: top-right
+        const right = ob.x + ob.w;
+        fx = Math.max(MIN, (right - world.x) / ob.w);
+        fy = Math.max(MIN, (world.y - ob.y) / ob.h);
+        const f = (fx + fy) / 2;
+        fx = f; fy = f;
+        break;
+      }
+      // --- Edge handles (proportional by default, hold Shift for free-form) ---
+      case 'mr': {
+        fx = Math.max(MIN, (world.x - ob.x) / ob.w);
+        if (!e.shiftKey) fy = fx;
+        break;
+      }
+      case 'ml': {
+        const right = ob.x + ob.w;
+        fx = Math.max(MIN, (right - world.x) / ob.w);
+        if (!e.shiftKey) fy = fx;
+        break;
+      }
+      case 'bc': {
+        fy = Math.max(MIN, (world.y - ob.y) / ob.h);
+        if (!e.shiftKey) fx = fy;
+        break;
+      }
+      case 'tc': {
+        const bottom = ob.y + ob.h;
+        fy = Math.max(MIN, (bottom - world.y) / ob.h);
+        if (!e.shiftKey) fx = fy;
+        break;
+      }
+    }
 
     for (const item of this._items) {
       const orig = origTransforms.get(item.id);
       if (!orig) continue;
 
+      // Apply scale factors relative to original
+      item.data.sx = orig.sx * fx;
+      item.data.sy = orig.sy * fy;
+
+      // Reposition to keep fixed edge in place
       switch (handleId) {
-        case 'br': {
+        case 'tl':
-          // Proportional scale — drag distance relative to object size
+          item.data.x = orig.x + (orig.sx - item.data.sx) * item.data.w;
-          const factor = 1 + (dx + dy) / refSize;
-          const clampedFactor = Math.max(0.05, factor);
-          item.data.sx = orig.sx * clampedFactor;
-          item.data.sy = orig.sy * clampedFactor;
-          break;
-        }
-        case 'mr': {
-          const factor = 1 + dx / (bw || refSize);
-          item.data.sx = orig.sx * Math.max(0.05, factor);
-          break;
-        }
-        case 'bc': {
-          const factor = 1 + dy / (bh || refSize);
-          item.data.sy = orig.sy * Math.max(0.05, factor);
-          break;
-        }
-        case 'tl': {
-          // Proportional scale + reposition (bottom-right stays fixed)
-          const factor = 1 - (dx + dy) / refSize;
-          const clampedFactor = Math.max(0.05, factor);
-          item.data.sx = orig.sx * clampedFactor;
-          item.data.sy = orig.sy * clampedFactor;
-          const dw = (item.data.sx - orig.sx) * item.data.w;
-          const dh = (item.data.sy - orig.sy) * item.data.h;
-          item.data.x = orig.x - dw;
-          item.data.y = orig.y - dh;
-          break;
-        }
-        case 'rot': {
-          // Rotation: 1 world pixel = ~0.3 degrees
-          item.data.angle = orig.angle + dx * 0.3;
-          break;
-        }
-        case 'tr': {
-          const factor = 1 + (dx - dy) / refSize;
-          const clampedFactor = Math.max(0.05, factor);
-          item.data.sx = orig.sx * clampedFactor;
-          item.data.sy = orig.sy * clampedFactor;
-          // Top-right: left edge stays fixed
-          item.data.y = orig.y - (item.data.sy - orig.sy) * item.data.h;
-          break;
-        }
-        case 'bl': {
-          const factor = 1 + (-dx + dy) / refSize;
-          const clampedFactor = Math.max(0.05, factor);
-          item.data.sx = orig.sx * clampedFactor;
-          item.data.sy = orig.sy * clampedFactor;
-          // Bottom-left: right edge stays fixed
-          item.data.x = orig.x - (item.data.sx - orig.sx) * item.data.w;
-          break;
-        }
-        case 'tc': {
-          const factor = 1 - dy / (bh || refSize);
-          item.data.sy = orig.sy * Math.max(0.05, factor);
-          // Top-center: bottom edge stays fixed
           item.data.y = orig.y + (orig.sy - item.data.sy) * item.data.h;
           break;
-        }
+        case 'tc':
-        case 'ml': {
+          item.data.y = orig.y + (orig.sy - item.data.sy) * item.data.h;
-          const factor = 1 - dx / (bw || refSize);
+          break;
-          item.data.sx = orig.sx * Math.max(0.05, factor);
+        case 'tr':
-          // Middle-left: right edge stays fixed
+          item.data.y = orig.y + (orig.sy - item.data.sy) * item.data.h;
+          break;
+        case 'ml':
           item.data.x = orig.x + (orig.sx - item.data.sx) * item.data.w;
           break;
-        }
+        case 'bl':
+          item.data.x = orig.x + (orig.sx - item.data.sx) * item.data.w;
+          break;
+        // br, mr, bc: top-left is fixed, no reposition needed
       }
 
-      // Apply to display object
       item.displayObject.scale.set(item.data.sx, item.data.sy);
-      item.displayObject.angle = item.data.angle;
       item.displayObject.position.set(item.data.x, item.data.y);
+
+      this._onItemTransform?.(item);
     }
 
-    // Redraw transform box around new bounds
     this.update(this._items);
+
+    // Snap guides during resize
+    if (this._snapGuides && this._viewport) {
+      const snap = this._snapGuides.computeSnap(this._bounds, this._viewport);
+      if (snap.dx !== 0 || snap.dy !== 0) {
+        // Apply snap correction to all items
+        for (const item of this._items) {
+          item.data.x += snap.dx;
+          item.data.y += snap.dy;
+          item.displayObject.position.set(item.data.x, item.data.y);
+          this._onItemTransform?.(item);
+        }
+        this.update(this._items);
+      }
+      this._snapGuides.drawGuides(snap.guides, this._viewport);
+    }
+
+    // Show dimension label
+    const bounds = this._bounds;
+    const zoom = this._viewport?.scale.x ?? 1;
+    const w = Math.round(bounds.w);
+    const h = Math.round(bounds.h);
+    this._dimLabel.text = `${w} \u00d7 ${h}`;
+    this._dimLabel.scale.set(1 / zoom); // Stay fixed screen size
+
+    // Position below bottom-right corner with offset
+    const labelX = bounds.x + bounds.w;
+    const labelY = bounds.y + bounds.h + 12 / zoom;
+    this._dimLabel.anchor.set(1, 0); // right-aligned
+    this._dimLabel.position.set(labelX, labelY);
+
+    // Background pill
+    const pad = 4 / zoom;
+    const textW = this._dimLabel.width;
+    const textH = this._dimLabel.height;
+    this._dimLabelBg.clear();
+    this._dimLabelBg.roundRect(
+      labelX - textW - pad,
+      labelY - pad / 2,
+      textW + pad * 2,
+      textH + pad,
+      3 / zoom,
+    );
+    this._dimLabelBg.fill({ color: 0x1a1a1a, alpha: 0.9 });
+
+    this._dimLabel.visible = true;
+    this._dimLabelBg.visible = true;
   }
 
   private _onHandleUp(): void {
     this._drag = null;
+    this._dimLabel.visible = false;
+    this._dimLabelBg.visible = false;
+    this._snapGuides?.endSession();
   }
 }

frontend/src/canvas/clipboard.ts

@@ -0,0 +1,178 @@
+/**
+ * Clipboard module — copy canvas to system clipboard and paste images from it.
+ *
+ * Copy approach: render ONLY the selected items at native resolution using
+ * PixiJS generateTexture + extract. No viewport cropping — independent of
+ * zoom/pan state. Items are temporarily reparented into a clean container,
+ * rendered, then restored.
+ */
+
+import { Container, Rectangle } from 'pixi.js';
+import type { Viewport } from 'pixi-viewport';
+import type { Application } from 'pixi.js';
+import type { SceneManager, SceneItem } from './SceneManager';
+import { getItemWorldBounds } from './SceneManager';
+import { uploadImage } from '../api';
+
+/**
+ * Write selected items (or full viewport) to system clipboard as PNG.
+ * Selected items are rendered at their native size, not affected by zoom.
+ */
+export async function writeCanvasToClipboard(
+  app: Application | null,
+  viewport: Viewport | null,
+  items?: SceneItem[],
+): Promise<void> {
+  if (!viewport) throw new Error('Viewport not available');
+  if (!app?.renderer?.extract) throw new Error('Renderer not available');
+
+  let outputCanvas: HTMLCanvasElement;
+
+  if (items && items.length > 0) {
+    // --- Render selected items at native resolution ---
+
+    // 1. Compute world-space bounding box
+    let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+    for (const item of items) {
+      const { x, y, w, h } = getItemWorldBounds(item);
+      minX = Math.min(minX, x);
+      minY = Math.min(minY, y);
+      maxX = Math.max(maxX, x + w);
+      maxY = Math.max(maxY, y + h);
+    }
+
+    const pad = 10;
+    const totalW = Math.ceil(maxX - minX) + pad * 2;
+    const totalH = Math.ceil(maxY - minY) + pad * 2;
+
+    // 2. Save original parent/transform for each item, reparent into temp container
+    const tempContainer = new Container();
+    const saved = new Map<string, {
+      parent: Container;
+      x: number;
+      y: number;
+      sx: number;
+      sy: number;
+    }>();
+
+    // Pre-compute world bounds for each item (handles group children with local coords)
+    const worldBoundsMap = new Map<string, { x: number; y: number; w: number; h: number }>();
+    for (const item of items) {
+      worldBoundsMap.set(item.id, getItemWorldBounds(item));
+    }
+
+    for (const item of items) {
+      const obj = item.displayObject;
+      saved.set(item.id, {
+        parent: obj.parent as Container,
+        x: obj.x,
+        y: obj.y,
+        sx: obj.scale.x,
+        sy: obj.scale.y,
+      });
+
+      // Remove from current parent
+      obj.parent?.removeChild(obj);
+
+      // Position using world bounds (correct for both top-level and group children)
+      const wb = worldBoundsMap.get(item.id)!;
+      obj.position.set(wb.x - minX + pad, wb.y - minY + pad);
+      // Use data scale (not viewport-affected scale)
+      obj.scale.set(item.data.sx, item.data.sy);
+
+      tempContainer.addChild(obj);
+    }
+
+    // 3. Generate texture at 1x resolution (native pixel size)
+    let texture;
+    let extractedCanvas: HTMLCanvasElement;
+    try {
+      texture = app.renderer.generateTexture({
+        target: tempContainer,
+        resolution: 1,
+        frame: new Rectangle(0, 0, totalW, totalH),
+      });
+      extractedCanvas = app.renderer.extract.canvas(texture) as HTMLCanvasElement;
+    } finally {
+      // 4. Restore items to their original parents and transforms (even on error)
+      for (const item of items) {
+        const s = saved.get(item.id)!;
+        tempContainer.removeChild(item.displayObject);
+        s.parent.addChild(item.displayObject);
+        item.displayObject.position.set(s.x, s.y);
+        item.displayObject.scale.set(s.sx, s.sy);
+      }
+      tempContainer.destroy();
+      texture?.destroy(true);
+    }
+
+    // 6. Add opaque background
+    outputCanvas = document.createElement('canvas');
+    outputCanvas.width = extractedCanvas.width;
+    outputCanvas.height = extractedCanvas.height;
+    const ctx2d = outputCanvas.getContext('2d')!;
+    ctx2d.fillStyle = '#1e1e1e';
+    ctx2d.fillRect(0, 0, outputCanvas.width, outputCanvas.height);
+    ctx2d.drawImage(extractedCanvas, 0, 0);
+  } else {
+    // Full viewport screenshot
+    const extractedCanvas = app.renderer.extract.canvas(viewport) as HTMLCanvasElement;
+    outputCanvas = document.createElement('canvas');
+    outputCanvas.width = extractedCanvas.width;
+    outputCanvas.height = extractedCanvas.height;
+    const ctx2d = outputCanvas.getContext('2d')!;
+    ctx2d.fillStyle = '#1e1e1e';
+    ctx2d.fillRect(0, 0, outputCanvas.width, outputCanvas.height);
+    ctx2d.drawImage(extractedCanvas, 0, 0);
+  }
+
+  const blob = await new Promise<Blob>((resolve, reject) => {
+    outputCanvas.toBlob((b) => {
+      if (b) resolve(b);
+      else reject(new Error('toBlob returned null'));
+    }, 'image/png');
+  });
+
+  await navigator.clipboard.write([
+    new ClipboardItem({ 'image/png': blob }),
+  ]);
+}
+
+/**
+ * Paste an image from the system clipboard into the scene.
+ * Reads the clipboard, uploads the first image found, and adds it at the viewport center.
+ */
+export async function pasteFromSystemClipboard(
+  scene: SceneManager,
+  viewport: Viewport,
+  boardId: string,
+  onChange: () => void,
+): Promise<string> {
+  const clipItems = await navigator.clipboard.read();
+  for (const clipItem of clipItems) {
+    for (const type of clipItem.types) {
+      if (!type.startsWith('image/')) continue;
+      const blob = await clipItem.getType(type);
+      const file = new File([blob], `paste.${type.split('/')[1]}`, { type });
+      const res = await uploadImage(boardId, file);
+      const imgData = res.data.image || res.data;
+      const assetKey = imgData.asset_key;
+      const w = imgData.width || 400;
+      const h = imgData.height || 300;
+      const maxDim = 600;
+      let fw = w, fh = h;
+      if (w > maxDim || h > maxDim) {
+        const s = maxDim / Math.max(w, h);
+        fw = Math.round(w * s);
+        fh = Math.round(h * s);
+      }
+      if (assetKey) {
+        const center = viewport.center;
+        scene.addImageFromUpload(assetKey, fw, fh, center.x - fw / 2, center.y - fh / 2);
+        onChange();
+        return 'Pasted image';
+      }
+    }
+  }
+  return 'No image in clipboard';
+}

frontend/src/canvas/context-menu-items.ts

@@ -0,0 +1,248 @@
+/**
+ * Context menu builder — assembles menu items from scene/selection state.
+ */
+
+import type { SceneManager, SceneItem } from './SceneManager';
+import type { SelectionManager } from './SelectionManager';
+import { getItemWorldBounds } from './SceneManager';
+import type { Viewport } from 'pixi-viewport';
+import type { GroupObject } from './scene-format';
+import { FrameSprite } from './sprites/FrameSprite';
+import * as ops from './operations';
+
+export interface MenuItem {
+  label: string;
+  shortcut: string;
+  onClick: () => void | Promise<void>;
+  disabled?: boolean;
+  divider?: boolean;
+  danger?: boolean;
+}
+
+interface MenuContext {
+  scene: SceneManager | null;
+  selection: SelectionManager | null;
+  viewport: Viewport | null;
+  clipboardRef: React.MutableRefObject<SceneItem[]>;
+  writeCanvasToClipboard: (items?: SceneItem[]) => Promise<void>;
+  onChange: () => void;
+  refreshLayers: () => void;
+  handleGroup: () => void;
+  handleUngroup: () => void;
+  fitAll: () => void;
+}
+
+export function buildContextMenuItems(ctx: MenuContext): MenuItem[] {
+  const { scene, selection, viewport } = ctx;
+  const selected = selection ? selection.getSelectedItems() : [];
+  const hasSel = selected.length > 0;
+  const multiSel = selected.length >= 2;
+
+  return [
+    // -- Clipboard --
+    { label: 'Copy', shortcut: 'Ctrl+C', onClick: () => {
+      if (hasSel) { ctx.clipboardRef.current = [...selected]; ctx.writeCanvasToClipboard(selected); }
+      else ctx.writeCanvasToClipboard();
+    } },
+    { label: 'Cut', shortcut: 'Ctrl+X', onClick: () => {
+      if (!scene || !hasSel || !selection) return;
+      ctx.clipboardRef.current = [...selected];
+      for (const item of selected) scene.removeItem(item.id, true);
+      selection.clear();
+      ctx.onChange();
+    }, disabled: !hasSel },
+    { label: 'Paste', shortcut: 'Ctrl+V', onClick: async () => {
+      if (!scene || ctx.clipboardRef.current.length === 0) return;
+      const cloned = _cloneWithGroupSupport(ctx.clipboardRef.current, scene);
+      const sorted = [...cloned].sort((a, b) =>
+        (a.type === 'group' ? 1 : 0) - (b.type === 'group' ? 1 : 0));
+      for (const newData of sorted) {
+        await scene._createItem(newData, true);
+      }
+      scene._applyZOrder();
+      ctx.onChange();
+    }, disabled: ctx.clipboardRef.current.length === 0 },
+    { label: 'Duplicate', shortcut: 'Ctrl+D', onClick: async () => {
+      if (!scene || !hasSel) return;
+      const allItems = _collectGroupChildren(selected, scene);
+      const cloned = _cloneWithGroupSupport(allItems, scene);
+      const sorted = [...cloned].sort((a, b) =>
+        (a.type === 'group' ? 1 : 0) - (b.type === 'group' ? 1 : 0));
+      for (const newData of sorted) {
+        await scene._createItem(newData, true);
+      }
+      if (selection) selection.clear();
+      scene._applyZOrder();
+      ctx.onChange();
+    }, disabled: !hasSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Alignment --
+    { label: 'Align Left', shortcut: 'Ctrl+\u2190', onClick: () => { ops.alignLeft(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Align Right', shortcut: 'Ctrl+\u2192', onClick: () => { ops.alignRight(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Align Top', shortcut: 'Ctrl+\u2191', onClick: () => { ops.alignTop(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Align Bottom', shortcut: 'Ctrl+\u2193', onClick: () => { ops.alignBottom(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Distribute H', shortcut: '', onClick: () => { ops.distributeHorizontal(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: selected.length < 3 },
+    { label: 'Distribute V', shortcut: '', onClick: () => { ops.distributeVertical(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: selected.length < 3 },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Layer ordering --
+    { label: 'Bring Forward', shortcut: ']', onClick: () => {
+      if (!scene) return;
+      const all = scene.getAllItems().sort((a, b) => a.data.z - b.data.z);
+      const selectedIds = new Set(selected.map((s) => s.id));
+      for (let i = all.length - 2; i >= 0; i--) {
+        if (selectedIds.has(all[i].id) && !selectedIds.has(all[i + 1].id)) {
+          const tmp = all[i].data.z;
+          all[i].data.z = all[i + 1].data.z;
+          all[i + 1].data.z = tmp;
+        }
+      }
+      scene._applyZOrder();
+      ctx.onChange();
+    }, disabled: !hasSel },
+    { label: 'Send Backward', shortcut: '[', onClick: () => {
+      if (!scene) return;
+      const all = scene.getAllItems().sort((a, b) => a.data.z - b.data.z);
+      const selectedIds = new Set(selected.map((s) => s.id));
+      for (let i = 1; i < all.length; i++) {
+        if (selectedIds.has(all[i].id) && !selectedIds.has(all[i - 1].id)) {
+          const tmp = all[i].data.z;
+          all[i].data.z = all[i - 1].data.z;
+          all[i - 1].data.z = tmp;
+        }
+      }
+      scene._applyZOrder();
+      ctx.onChange();
+    }, disabled: !hasSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Group --
+    { label: 'Group', shortcut: 'Ctrl+G', onClick: ctx.handleGroup, disabled: !multiSel },
+    { label: 'Ungroup', shortcut: 'Ctrl+Shift+G', onClick: ctx.handleUngroup,
+      disabled: selected.length !== 1 || selected[0]?.data.type !== 'group' },
+    // Frame color (for selected group/frame)
+    ...(selected.length === 1 && selected[0]?.data.type === 'group' ? [
+      { label: 'Frame: Blue', shortcut: '', onClick: () => _setFrameColor(selected[0], '#4a90d9', ctx) },
+      { label: 'Frame: Green', shortcut: '', onClick: () => _setFrameColor(selected[0], '#69db7c', ctx) },
+      { label: 'Frame: Red', shortcut: '', onClick: () => _setFrameColor(selected[0], '#ff6b6b', ctx) },
+      { label: 'Frame: Purple', shortcut: '', onClick: () => _setFrameColor(selected[0], '#7950f2', ctx) },
+      { label: 'Frame: Cyan', shortcut: '', onClick: () => _setFrameColor(selected[0], '#38d9a9', ctx) },
+      { label: 'Frame: Orange', shortcut: '', onClick: () => _setFrameColor(selected[0], '#ffa94d', ctx) },
+      { label: 'Frame: None', shortcut: '', onClick: () => _setFrameColor(selected[0], '', ctx) },
+    ] as MenuItem[] : []),
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Arrangement --
+    { label: 'Arrange Pack', shortcut: 'Ctrl+Shift+P', onClick: () => { ops.arrangeOptimal(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Arrange Grid', shortcut: '', onClick: () => { ops.arrangeGrid(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Arrange Row', shortcut: '', onClick: () => { ops.arrangeRow(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Arrange Column', shortcut: '', onClick: () => { ops.arrangeColumn(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Stack', shortcut: 'Ctrl+Alt+S', onClick: () => { ops.stackObjects(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Normalize --
+    { label: 'Normalize Size', shortcut: '', onClick: () => { ops.normalizeSize(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Normalize Width', shortcut: '', onClick: () => { ops.normalizeWidth(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: 'Normalize Height', shortcut: '', onClick: () => { ops.normalizeHeight(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !multiSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Image --
+    { label: 'Flip Horizontal', shortcut: 'Alt+Shift+H', onClick: () => { ops.flipHorizontal(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !hasSel },
+    { label: 'Flip Vertical', shortcut: 'Alt+Shift+V', onClick: () => { ops.flipVertical(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !hasSel },
+    { label: 'Reset Transform', shortcut: 'Ctrl+Shift+T', onClick: () => { ops.resetTransform(selected); selection?.transformBox.update(selected); ctx.onChange(); }, disabled: !hasSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- View --
+    { label: 'Select All', shortcut: 'Ctrl+A', onClick: () => { if (selection) selection.selectAll(); } },
+    { label: 'Fit All', shortcut: 'Ctrl+0', onClick: ctx.fitAll },
+    { label: 'Fit Selection', shortcut: 'F', onClick: () => {
+      if (!selection || !viewport) return;
+      const items = selection.getSelectedItems();
+      if (items.length === 0) return;
+      let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+      for (const item of items) {
+        const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
+        if (ix < minX) minX = ix;
+        if (iy < minY) minY = iy;
+        if (ix + iw > maxX) maxX = ix + iw;
+        if (iy + ih > maxY) maxY = iy + ih;
+      }
+      const pad = 60;
+      const cw = maxX - minX + pad * 2;
+      const ch = maxY - minY + pad * 2;
+      const s = Math.min(viewport.screenWidth / cw, viewport.screenHeight / ch, 5);
+      viewport.animate({ position: { x: (minX + maxX) / 2, y: (minY + maxY) / 2 }, scale: s, time: 300, ease: 'easeOutQuad' });
+    }, disabled: !hasSel },
+    { label: '', shortcut: '', onClick: () => {}, divider: true },
+
+    // -- Delete --
+    { label: 'Delete', shortcut: 'Del', onClick: () => {
+      if (!scene || !selection) return;
+      for (const item of selected) scene.removeItem(item.id, true);
+      selection.clear();
+      ctx.onChange();
+    }, disabled: !hasSel, danger: true },
+  ];
+}
+
+/** Collect selected items + their group children (for deep clone). */
+function _collectGroupChildren(items: SceneItem[], scene: SceneManager): SceneItem[] {
+  const all: SceneItem[] = [];
+  const seen = new Set<string>();
+  for (const item of items) {
+    if (seen.has(item.id)) continue;
+    seen.add(item.id);
+    all.push(item);
+    if (item.data.type === 'group') {
+      const gd = item.data as GroupObject;
+      for (const cid of gd.children) {
+        if (seen.has(cid)) continue;
+        seen.add(cid);
+        const child = scene.getById(cid);
+        if (child) all.push(child);
+      }
+    }
+  }
+  return all;
+}
+
+/** Clone items with new IDs, remapping group children references. */
+function _cloneWithGroupSupport(items: SceneItem[], scene: SceneManager): any[] {
+  // Expand: include group children that aren't explicitly in the list
+  const expanded = _collectGroupChildren(items, scene);
+
+  const idMap = new Map<string, string>();
+  for (const item of expanded) {
+    idMap.set(item.data.id, crypto.randomUUID());
+  }
+
+  const clones: any[] = [];
+  for (const item of expanded) {
+    const newId = idMap.get(item.data.id)!;
+    const newData = {
+      ...item.data,
+      id: newId,
+      x: item.data.x + 20,
+      y: item.data.y + 20,
+      z: scene.nextZ(),
+    };
+    if (newData.type === 'group' && Array.isArray(newData.children)) {
+      newData.children = newData.children
+        .map((cid: string) => idMap.get(cid))
+        .filter((c): c is string => !!c);
+    }
+    clones.push(newData);
+  }
+  return clones;
+}
+
+/** Set the background color of a group/frame. */
+function _setFrameColor(item: SceneItem, color: string, ctx: MenuContext): void {
+  const gd = item.data as GroupObject;
+  gd.bgColor = color;
+  if (item.displayObject instanceof FrameSprite) {
+    item.displayObject.setBgColor(color);
+  }
+  ctx.onChange();
+}

frontend/src/canvas/grouping.ts

@@ -0,0 +1,197 @@
+/**
+ * Grouping module — group/ungroup operations for scene items.
+ *
+ * Data model:
+ *  - Group children store LOCAL x/y (relative to group origin) in data.x/y
+ *  - The group's data.x/y is the world-space top-left of the bounding box
+ *  - On serialize, children's data.x/y are local coords → correct on reload
+ *  - On ungroup, children's data.x/y are converted back to world coords
+ */
+
+import type { Viewport } from 'pixi-viewport';
+import type { SceneManager, SceneItem } from './SceneManager';
+import { getItemWorldBounds, rebuildGroupChildSet } from './SceneManager';
+import type { SelectionManager } from './SelectionManager';
+import type { GroupObject } from './scene-format';
+import { randomFrameColor } from './sprites/FrameSprite';
+
+/**
+ * Group selected items into a single group container.
+ * Requires at least 2 selected items.
+ */
+export function groupItems(
+  scene: SceneManager,
+  selection: SelectionManager,
+  onChange: () => void,
+): void {
+  const selected = selection.getSelectedItems();
+  if (selected.length < 2) return;
+
+  // Allow nested groups — groups can contain other groups
+
+  // Compute the bounding box of all selected items
+  let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+  for (const item of selected) {
+    const b = getItemWorldBounds(item);
+    minX = Math.min(minX, b.x);
+    minY = Math.min(minY, b.y);
+    maxX = Math.max(maxX, b.x + b.w);
+    maxY = Math.max(maxY, b.y + b.h);
+  }
+
+  const groupX = minX;
+  const groupY = minY;
+  const groupW = maxX - minX;
+  const groupH = maxY - minY;
+
+  const groupData: GroupObject = {
+    id: crypto.randomUUID(),
+    type: 'group',
+    x: groupX,
+    y: groupY,
+    w: groupW,
+    h: groupH,
+    sx: 1,
+    sy: 1,
+    angle: 0,
+    z: scene.nextZ(),
+    opacity: 1,
+    locked: false,
+    name: '',
+    visible: true,
+    children: selected.map((s) => s.id),
+    bgColor: randomFrameColor(),
+    label: '',
+    padding: 12,
+  };
+
+  // Create the group container
+  scene._createItem(groupData, false);
+  const groupItem = scene.getById(groupData.id);
+  if (!groupItem) return;
+
+  // Reparent each selected item into the group container
+  for (const child of selected) {
+    const obj = child.displayObject;
+
+    // Convert world position to local (relative to group origin)
+    const localX = child.data.x - groupX;
+    const localY = child.data.y - groupY;
+
+    // Update DATA to store local coords (critical for serialization)
+    child.data.x = localX;
+    child.data.y = localY;
+
+    // Reparent display object
+    obj.parent?.removeChild(obj);
+    obj.position.set(localX, localY);
+    groupItem.displayObject.addChild(obj);
+  }
+
+  selection.clear();
+  selection.selectOnly(groupItem.id);
+  rebuildGroupChildSet(scene);
+  scene._applyZOrder();
+  onChange();
+}
+
+/**
+ * Ungroup the selected group, reparenting children back to the viewport.
+ * Propagates group's scale, angle, and opacity to each child so visual
+ * appearance is preserved after ungrouping.
+ * Requires exactly 1 selected item of type 'group'.
+ */
+export function ungroupItems(
+  scene: SceneManager,
+  selection: SelectionManager,
+  viewport: Viewport,
+  onChange: () => void,
+): void {
+  const selected = selection.getSelectedItems();
+  if (selected.length !== 1) return;
+  const groupItem = selected[0];
+  if (groupItem.data.type !== 'group') return;
+
+  const groupData = groupItem.data as GroupObject;
+  const groupX = groupData.x;
+  const groupY = groupData.y;
+  const groupSx = groupData.sx;
+  const groupSy = groupData.sy;
+  const groupAngle = groupData.angle;
+  const childIds: string[] = [];
+
+  // Reparent each child back to the viewport, propagating group transforms
+  for (const childId of groupData.children) {
+    const childItem = scene.getById(childId);
+    if (!childItem) continue;
+
+    const obj = childItem.displayObject;
+
+    // Convert local position to world space, accounting for group scale
+    const worldX = groupX + childItem.data.x * groupSx;
+    const worldY = groupY + childItem.data.y * groupSy;
+
+    // Propagate group scale to child
+    childItem.data.sx *= groupSx;
+    childItem.data.sy *= groupSy;
+
+    // Propagate group angle to child
+    childItem.data.angle = (childItem.data.angle || 0) + groupAngle;
+
+    // Update DATA to store world coords
+    childItem.data.x = worldX;
+    childItem.data.y = worldY;
+
+    // Reparent display object
+    obj.parent?.removeChild(obj);
+    viewport.addChild(obj);
+    obj.position.set(worldX, worldY);
+    obj.scale.set(childItem.data.sx, childItem.data.sy);
+    obj.angle = childItem.data.angle;
+
+    childIds.push(childId);
+  }
+
+  // Remove the group item itself (don't destroy children — they're reparented)
+  const groupObj = groupItem.displayObject;
+  groupObj.parent?.removeChild(groupObj);
+  groupObj.destroy();
+  scene.items.delete(groupItem.id);
+
+  // Select the ungrouped children
+  selection.clear();
+  for (const id of childIds) {
+    selection.selectedIds.add(id);
+  }
+  selection.transformBox.update(selection.getSelectedItems());
+
+  rebuildGroupChildSet(scene);
+  scene._applyZOrder();
+  onChange();
+}
+
+/**
+ * After loading a scene, reparent group children into their group containers.
+ * Called by SceneManager.loadScene() after all items are created.
+ */
+export function reparentGroupChildren(scene: SceneManager): void {
+  for (const item of scene.items.values()) {
+    if (item.data.type !== 'group') continue;
+    const groupData = item.data as GroupObject;
+    const groupContainer = item.displayObject;
+
+    for (const childId of groupData.children) {
+      const childItem = scene.getById(childId);
+      if (!childItem) continue;
+
+      const obj = childItem.displayObject;
+      // Only reparent if currently in viewport (not already in a group)
+      if (obj.parent !== groupContainer) {
+        obj.parent?.removeChild(obj);
+        // data.x/y are already local coords (saved that way)
+        obj.position.set(childItem.data.x, childItem.data.y);
+        groupContainer.addChild(obj);
+      }
+    }
+  }
+}

frontend/src/canvas/image-drop.ts

@@ -1,7 +1,6 @@
 import { Graphics } from 'pixi.js';
 import type { Viewport } from 'pixi-viewport';
 import type { SceneManager } from './SceneManager';
-import { VideoSprite } from './sprites/VideoSprite';
 import { uploadImage, uploadImageFromUrl } from '../api';
 
 type OnChange = () => void;
@@ -55,10 +54,7 @@ function handleUploadResult(
   }
 
   if (mediaType === 'video' && assetKey) {
-    const url = imgData.public_url;
+    sceneManager.addVideoFromUpload(assetKey, finalW, finalH, x, y);
-    const video = new VideoSprite(assetKey, finalW, finalH, url);
-    video.position.set(x, y);
-    viewport.addChild(video);
   } else if (assetKey) {
     sceneManager.addImageFromUpload(assetKey, finalW, finalH, x, y);
   } else {
@@ -122,18 +118,23 @@ export function setupDragDrop(
       return;
     }
 
+    let dropIndex = 0;
     for (let i = 0; i < files.length; i++) {
       const file = files[i];
       if (!file.type.startsWith('image/') && !file.type.startsWith('video/')) continue;
 
       const rect = container.getBoundingClientRect();
       const world = viewport.toWorld(e.clientX - rect.left, e.clientY - rect.top);
-      const placeholder = createPlaceholder(viewport, world.x, world.y);
+      // Offset each subsequent file so they don't overlap
+      const offsetX = dropIndex * 30;
+      const offsetY = dropIndex * 30;
+      const placeholder = createPlaceholder(viewport, world.x + offsetX, world.y + offsetY);
+      dropIndex++;
 
       try {
         const res = await uploadImage(boardId, file);
         removePlaceholder(viewport, placeholder);
-        handleUploadResult(res, viewport, sceneManager, world.x, world.y, onChange);
+        handleUploadResult(res, viewport, sceneManager, world.x + offsetX, world.y + offsetY, onChange);
       } catch (err) {
         console.error('Image upload failed:', err);
         removePlaceholder(viewport, placeholder);
@@ -141,10 +142,22 @@ export function setupDragDrop(
     }
   }
 
+  // Prevent browser default (opening file in new tab) on the whole document
+  function onDocDragOver(e: DragEvent) {
+    e.preventDefault();
+  }
+  function onDocDrop(e: DragEvent) {
+    e.preventDefault();
+  }
+
+  document.addEventListener('dragover', onDocDragOver);
+  document.addEventListener('drop', onDocDrop);
   container.addEventListener('dragover', onDragOver);
   container.addEventListener('drop', onDrop);
 
   return () => {
+    document.removeEventListener('dragover', onDocDragOver);
+    document.removeEventListener('drop', onDocDrop);
     container.removeEventListener('dragover', onDragOver);
     container.removeEventListener('drop', onDrop);
   };

frontend/src/canvas/operations.ts

@@ -350,6 +350,94 @@ export function toggleLocked(objects: SceneItem[]) {
   });
 }
 
+// ─── Nudge ───
+
+export function nudge(objects: SceneItem[], dx: number, dy: number) {
+  objects.forEach((item) => {
+    item.data.x += dx;
+    item.data.y += dy;
+    syncPosition(item);
+  });
+}
+
+// ─── Scale (relative) ───
+
+export function scaleBy(objects: SceneItem[], factor: number) {
+  objects.forEach((item) => {
+    const cx = item.data.x + scaledW(item) / 2;
+    const cy = item.data.y + scaledH(item) / 2;
+    item.data.sx *= factor;
+    item.data.sy *= factor;
+    // Keep center in place
+    item.data.x = cx - scaledW(item) / 2;
+    item.data.y = cy - scaledH(item) / 2;
+    syncTransform(item);
+  });
+}
+
+// ─── Rotate (quick 90° snap) ───
+
+export function rotate90(objects: SceneItem[], clockwise: boolean) {
+  objects.forEach((item) => {
+    item.data.angle = ((item.data.angle + (clockwise ? 90 : -90)) % 360 + 360) % 360;
+    item.displayObject.angle = item.data.angle;
+  });
+}
+
+// ─── Set Opacity ───
+
+export function setOpacity(objects: SceneItem[], opacity: number) {
+  const clamped = Math.max(0, Math.min(1, opacity));
+  objects.forEach((item) => {
+    item.data.opacity = clamped;
+    item.displayObject.alpha = clamped;
+  });
+}
+
+// ─── Align Center ───
+
+export function alignCenterH(objects: SceneItem[]) {
+  if (objects.length < 2) return;
+  const avgCX = objects.reduce((s, item) => s + item.data.x + scaledW(item) / 2, 0) / objects.length;
+  objects.forEach((item) => {
+    item.data.x = avgCX - scaledW(item) / 2;
+    syncPosition(item);
+  });
+}
+
+export function alignCenterV(objects: SceneItem[]) {
+  if (objects.length < 2) return;
+  const avgCY = objects.reduce((s, item) => s + item.data.y + scaledH(item) / 2, 0) / objects.length;
+  objects.forEach((item) => {
+    item.data.y = avgCY - scaledH(item) / 2;
+    syncPosition(item);
+  });
+}
+
+// ─── Equal Spacing ───
+
+export function equalSpacingH(objects: SceneItem[], gap = 20) {
+  if (objects.length < 2) return;
+  const sorted = [...objects].sort((a, b) => a.data.x - b.data.x);
+  let x = sorted[0].data.x + scaledW(sorted[0]) + gap;
+  for (let i = 1; i < sorted.length; i++) {
+    sorted[i].data.x = x;
+    syncPosition(sorted[i]);
+    x += scaledW(sorted[i]) + gap;
+  }
+}
+
+export function equalSpacingV(objects: SceneItem[], gap = 20) {
+  if (objects.length < 2) return;
+  const sorted = [...objects].sort((a, b) => a.data.y - b.data.y);
+  let y = sorted[0].data.y + scaledH(sorted[0]) + gap;
+  for (let i = 1; i < sorted.length; i++) {
+    sorted[i].data.y = y;
+    syncPosition(sorted[i]);
+    y += scaledH(sorted[i]) + gap;
+  }
+}
+
 // ─── Overlay / Compare ───
 
 export function overlayCompare(objects: SceneItem[]) {

frontend/src/canvas/scene-format.ts

@@ -4,7 +4,7 @@
 
 export interface SceneObject {
   id: string;
-  type: 'image' | 'video' | 'text' | 'group';
+  type: 'image' | 'video' | 'text' | 'group' | 'drawing';
   x: number;
   y: number;
   w: number;
@@ -42,12 +42,22 @@ export interface TextObject extends SceneObject {
   fontFamily: string;
 }
 
+export interface DrawingObject extends SceneObject {
+  type: 'drawing';
+  points: number[];   // flat array: [x0, y0, x1, y1, ...]
+  color: string;
+  strokeWidth: number;
+}
+
 export interface GroupObject extends SceneObject {
   type: 'group';
   children: string[];
+  bgColor?: string;   // frame background color (e.g. '#2a2a3a'), empty/undefined = transparent
+  label?: string;      // frame title label
+  padding?: number;    // inner padding around children (default 12)
 }
 
-export type AnySceneObject = ImageObject | VideoObject | TextObject | GroupObject;
+export type AnySceneObject = ImageObject | VideoObject | TextObject | DrawingObject | GroupObject;
 
 export interface SceneData {
   v: 2;

frontend/src/canvas/shortcut-definitions.ts

@@ -13,9 +13,103 @@
  * - Added Ctrl+S (prevent browser save-as)
  */
 
-import { ShortcutDef } from './shortcuts';
+import { ShortcutDef, ShortcutContext } from './shortcuts';
+import type { SceneItem, SceneManager } from './SceneManager';
+import type { GroupObject } from './scene-format';
 import * as ops from './operations';
 
+// Tracks when the last internal copy happened so paste can decide
+// whether to use internal clipboard (just copied) vs system clipboard (external app).
+let _lastInternalCopyTime = 0;
+
+/** Mark that an internal copy just happened. Called by copy/cut handlers. */
+export function markInternalCopy(): void {
+  _lastInternalCopyTime = Date.now();
+}
+
+/** Collect selected items + their group children (for deep clone). */
+function _collectGroupChildren(items: SceneItem[], scene: SceneManager): SceneItem[] {
+  const all: SceneItem[] = [];
+  const seen = new Set<string>();
+  for (const item of items) {
+    if (seen.has(item.id)) continue;
+    seen.add(item.id);
+    all.push(item);
+    if (item.data.type === 'group') {
+      const gd = item.data as GroupObject;
+      for (const cid of gd.children) {
+        if (seen.has(cid)) continue;
+        seen.add(cid);
+        const child = scene.getById(cid);
+        if (child) all.push(child);
+      }
+    }
+  }
+  return all;
+}
+
+/** Deep-clone a list of scene items, remapping group children IDs. */
+function _cloneItemsWithOffset(
+  items: { data: any }[],
+  scene: { nextZ: () => number },
+  offsetX = 20,
+  offsetY = 20,
+): any[] {
+  // First pass: build old→new ID mapping for all items
+  const idMap = new Map<string, string>();
+  for (const item of items) {
+    idMap.set(item.data.id, crypto.randomUUID());
+  }
+
+  // Second pass: clone data with new IDs and remapped children
+  const clones: any[] = [];
+  for (const item of items) {
+    const newId = idMap.get(item.data.id)!;
+    const newData = {
+      ...item.data,
+      id: newId,
+      x: item.data.x + offsetX,
+      y: item.data.y + offsetY,
+      z: scene.nextZ(),
+    };
+    // Remap group children references
+    if (newData.type === 'group' && Array.isArray(newData.children)) {
+      newData.children = newData.children
+        .map((cid: string) => idMap.get(cid) ?? cid)
+        .filter((cid: string) => idMap.has(cid) || items.some((i) => i.data.id === cid));
+    }
+    clones.push(newData);
+  }
+  return clones;
+}
+
+/** Paste from internal clipboard — duplicates scene items with offset. */
+async function _pasteInternal(ctx: ShortcutContext): Promise<void> {
+  const clones = _cloneItemsWithOffset(ctx.clipboardRef.current, ctx.scene);
+  const newItems: typeof ctx.clipboardRef.current = [];
+
+  // Create children first, then groups (so children exist when group is created)
+  const sorted = [...clones].sort((a, b) =>
+    (a.type === 'group' ? 1 : 0) - (b.type === 'group' ? 1 : 0));
+
+  for (const newData of sorted) {
+    await ctx.scene._createItem(newData, true);
+    const newItem = ctx.scene.getById(newData.id);
+    if (newItem) newItems.push(newItem);
+  }
+  ctx.clipboardRef.current = newItems;
+  ctx.scene._applyZOrder();
+  ctx.onChange();
+}
+
+/** Run op on selected items → update transform box → fire onChange. */
+function _opUpdate(ctx: ShortcutContext, op: (items: SceneItem[]) => void): void {
+  const items = ctx.selection.getSelectedItems();
+  op(items);
+  ctx.selection.transformBox.update(items);
+  ctx.onChange();
+}
+
 export const shortcuts: ShortcutDef[] = [
 
   // ═══════════════════════════════════════
@@ -25,34 +119,22 @@ export const shortcuts: ShortcutDef[] = [
   {
     id: 'align-left', keys: { key: 'arrowleft', ctrl: true },
     category: 'alignment', description: 'Align left', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.alignLeft),
-      ops.alignLeft(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'align-right', keys: { key: 'arrowright', ctrl: true },
     category: 'alignment', description: 'Align right', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.alignRight),
-      ops.alignRight(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'align-top', keys: { key: 'arrowup', ctrl: true },
     category: 'alignment', description: 'Align top', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.alignTop),
-      ops.alignTop(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'align-bottom', keys: { key: 'arrowdown', ctrl: true },
     category: 'alignment', description: 'Align bottom', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.alignBottom),
-      ops.alignBottom(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
 
   // ═══════════════════════════════════════
@@ -62,18 +144,12 @@ export const shortcuts: ShortcutDef[] = [
   {
     id: 'distribute-h', keys: { key: 'arrowup', ctrl: true, alt: true, shift: true },
     category: 'alignment', description: 'Distribute horizontal', needsSelection: true, minSelection: 3,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.distributeHorizontal),
-      ops.distributeHorizontal(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'distribute-v', keys: { key: 'arrowdown', ctrl: true, alt: true, shift: true },
     category: 'alignment', description: 'Distribute vertical', needsSelection: true, minSelection: 3,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.distributeVertical),
-      ops.distributeVertical(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
 
   // ═══════════════════════════════════════
@@ -83,34 +159,22 @@ export const shortcuts: ShortcutDef[] = [
   {
     id: 'normalize-size', keys: { key: 'arrowup', ctrl: true, alt: true },
     category: 'normalize', description: 'Normalize size (same area)', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.normalizeSize),
-      ops.normalizeSize(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'normalize-scale', keys: { key: 'arrowdown', ctrl: true, alt: true },
     category: 'normalize', description: 'Normalize scale', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.normalizeScale),
-      ops.normalizeScale(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'normalize-height', keys: { key: 'arrowleft', ctrl: true, alt: true },
     category: 'normalize', description: 'Normalize height', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.normalizeHeight),
-      ops.normalizeHeight(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'normalize-width', keys: { key: 'arrowright', ctrl: true, alt: true },
     category: 'normalize', description: 'Normalize width', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.normalizeWidth),
-      ops.normalizeWidth(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
 
   // ═══════════════════════════════════════
@@ -120,42 +184,27 @@ export const shortcuts: ShortcutDef[] = [
   {
     id: 'arrange-optimal', keys: { key: 'p', ctrl: true, shift: true },
     category: 'arrangement', description: 'Arrange optimal (pack)', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.arrangeOptimal),
-      ops.arrangeOptimal(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'arrange-by-name', keys: { key: 'n', ctrl: true, alt: true },
     category: 'arrangement', description: 'Arrange by name', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.arrangeByName),
-      ops.arrangeByName(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'arrange-by-order', keys: { key: 'o', ctrl: true, alt: true },
     category: 'arrangement', description: 'Arrange by z-order', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.arrangeByZOrder),
-      ops.arrangeByZOrder(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'arrange-random', keys: { key: 'r', ctrl: true, alt: true },
     category: 'arrangement', description: 'Arrange randomly', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.arrangeRandomly),
-      ops.arrangeRandomly(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'stack', keys: { key: 's', ctrl: true, alt: true },
     category: 'arrangement', description: 'Stack (pile on top)', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.stackObjects),
-      ops.stackObjects(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
 
   // ═══════════════════════════════════════
@@ -165,26 +214,17 @@ export const shortcuts: ShortcutDef[] = [
   {
     id: 'flip-h', keys: { key: 'h', alt: true, shift: true },
     category: 'image', description: 'Flip horizontal', needsSelection: true,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.flipHorizontal),
-      ops.flipHorizontal(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'flip-v', keys: { key: 'v', alt: true, shift: true },
     category: 'image', description: 'Flip vertical', needsSelection: true,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.flipVertical),
-      ops.flipVertical(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'reset-transform', keys: { key: 't', ctrl: true, shift: true },
     category: 'image', description: 'Reset transform', needsSelection: true,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.resetTransform),
-      ops.resetTransform(ctx.selection.getSelectedItems());
-      ctx.onChange();
-    },
   },
   {
     id: 'toggle-grayscale', keys: { key: 'g', alt: true },
@@ -199,16 +239,95 @@ export const shortcuts: ShortcutDef[] = [
     category: 'image', description: 'Toggle locked', needsSelection: true,
     handler: (ctx) => {
       ops.toggleLocked(ctx.selection.getSelectedItems());
+      ctx.onChange();
       ctx.refreshLayers();
     },
   },
   {
     id: 'overlay-compare', keys: { key: 'y', ctrl: true, shift: true },
     category: 'image', description: 'Overlay / compare', needsSelection: true, minSelection: 2,
-    handler: (ctx) => {
+    handler: (ctx) => _opUpdate(ctx, ops.overlayCompare),
-      ops.overlayCompare(ctx.selection.getSelectedItems());
+  },
-      ctx.onChange();
+
-    },
+  // ═══════════════════════════════════════
+  //  NUDGE  (Arrow keys with selection)
+  // ═══════════════════════════════════════
+
+  // Shift+Arrow = 10px nudge (more specific, checked first)
+  {
+    id: 'nudge-left-10', keys: { key: 'arrowleft', shift: true },
+    category: 'arrangement', description: 'Nudge left 10px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, -10, 0)),
+  },
+  {
+    id: 'nudge-right-10', keys: { key: 'arrowright', shift: true },
+    category: 'arrangement', description: 'Nudge right 10px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, 10, 0)),
+  },
+  {
+    id: 'nudge-up-10', keys: { key: 'arrowup', shift: true },
+    category: 'arrangement', description: 'Nudge up 10px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, 0, -10)),
+  },
+  {
+    id: 'nudge-down-10', keys: { key: 'arrowdown', shift: true },
+    category: 'arrangement', description: 'Nudge down 10px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, 0, 10)),
+  },
+
+  // ═══════════════════════════════════════
+  //  SCALE & ROTATE (selection)
+  // ═══════════════════════════════════════
+
+  {
+    id: 'scale-up', keys: { key: '=', alt: true },
+    category: 'image', description: 'Scale up 10%', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.scaleBy(items, 1.1)),
+  },
+  {
+    id: 'scale-down', keys: { key: '-', alt: true },
+    category: 'image', description: 'Scale down 10%', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.scaleBy(items, 1 / 1.1)),
+  },
+  {
+    id: 'rotate-cw', keys: { key: 'r' },
+    category: 'image', description: 'Rotate 90° clockwise', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.rotate90(items, true)),
+  },
+  {
+    id: 'rotate-ccw', keys: { key: 'r', shift: true },
+    category: 'image', description: 'Rotate 90° counter-clockwise', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.rotate90(items, false)),
+  },
+
+  // ═══════════════════════════════════════
+  //  ALIGN CENTER
+  // ═══════════════════════════════════════
+
+  {
+    id: 'align-center-h', keys: { key: 'arrowleft', ctrl: true, shift: true },
+    category: 'alignment', description: 'Align center horizontal', needsSelection: true, minSelection: 2,
+    handler: (ctx) => _opUpdate(ctx, ops.alignCenterH),
+  },
+  {
+    id: 'align-center-v', keys: { key: 'arrowup', ctrl: true, shift: true },
+    category: 'alignment', description: 'Align center vertical', needsSelection: true, minSelection: 2,
+    handler: (ctx) => _opUpdate(ctx, ops.alignCenterV),
+  },
+
+  // ═══════════════════════════════════════
+  //  EQUAL SPACING
+  // ═══════════════════════════════════════
+
+  {
+    id: 'equal-spacing-h', keys: { key: 'h', ctrl: true, shift: true },
+    category: 'arrangement', description: 'Equal horizontal spacing', needsSelection: true, minSelection: 2,
+    handler: (ctx) => _opUpdate(ctx, ops.equalSpacingH),
+  },
+  {
+    id: 'equal-spacing-v', keys: { key: 'v', ctrl: true, shift: true },
+    category: 'arrangement', description: 'Equal vertical spacing', needsSelection: true, minSelection: 2,
+    handler: (ctx) => _opUpdate(ctx, ops.equalSpacingV),
   },
 
   // ═══════════════════════════════════════
@@ -227,32 +346,55 @@ export const shortcuts: ShortcutDef[] = [
     category: 'navigation', description: 'Fit all in view',
     handler: (ctx) => ctx.fitAll(),
   },
-  // Bare arrow Left/Right only cycle when nothing is selected.
-  // When something IS selected, they're no-ops (prevent accidental cycling).
-  // Layer ordering uses ] / [ to avoid arrow conflicts.
   {
-    id: 'cycle-next', keys: { key: 'arrowright' },
+    id: 'focus-selection', keys: { key: 'f' },
-    category: 'navigation', description: 'Select next object',
+    category: 'navigation', description: 'Fit selection in view', needsSelection: true,
+    handler: (ctx) => ctx.fitSelection(),
+  },
+  {
+    id: 'toggle-focus-mode', keys: { key: 'tab' },
+    category: 'view', description: 'Toggle focus mode (hide UI)',
+    handler: (ctx) => ctx.toggleFocusMode(),
+  },
+  // Bare arrows: nudge 1px if selection, cycle if no selection
+  {
+    id: 'nudge-or-cycle-right', keys: { key: 'arrowright' },
+    category: 'navigation', description: 'Nudge 1px / Select next',
     handler: (ctx) => {
-      if (ctx.selection.selectedIds.size > 0) return;
+      if (ctx.selection.selectedIds.size > 0) {
-      const all = ctx.scene.getAllItems();
+        _opUpdate(ctx, (items) => ops.nudge(items, 1, 0));
-      if (all.length === 0) return;
+      } else {
-      // Sort by z to get consistent order
+        const all = ctx.scene.getAllItems();
-      all.sort((a, b) => a.data.z - b.data.z);
+        if (all.length === 0) return;
-      ctx.selection.selectOnly(all[0].id);
+        all.sort((a, b) => a.data.z - b.data.z);
+        ctx.selection.selectOnly(all[0].id);
+      }
     },
   },
   {
-    id: 'cycle-prev', keys: { key: 'arrowleft' },
+    id: 'nudge-or-cycle-left', keys: { key: 'arrowleft' },
-    category: 'navigation', description: 'Select previous object',
+    category: 'navigation', description: 'Nudge 1px / Select prev',
     handler: (ctx) => {
-      if (ctx.selection.selectedIds.size > 0) return;
+      if (ctx.selection.selectedIds.size > 0) {
-      const all = ctx.scene.getAllItems();
+        _opUpdate(ctx, (items) => ops.nudge(items, -1, 0));
-      if (all.length === 0) return;
+      } else {
-      all.sort((a, b) => a.data.z - b.data.z);
+        const all = ctx.scene.getAllItems();
-      ctx.selection.selectOnly(all[all.length - 1].id);
+        if (all.length === 0) return;
+        all.sort((a, b) => a.data.z - b.data.z);
+        ctx.selection.selectOnly(all[all.length - 1].id);
+      }
     },
   },
+  {
+    id: 'nudge-up', keys: { key: 'arrowup' },
+    category: 'navigation', description: 'Nudge up 1px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, 0, -1)),
+  },
+  {
+    id: 'nudge-down', keys: { key: 'arrowdown' },
+    category: 'navigation', description: 'Nudge down 1px', needsSelection: true,
+    handler: (ctx) => _opUpdate(ctx, (items) => ops.nudge(items, 0, 1)),
+  },
   // Layer ordering: ] brings forward, [ sends backward
   {
     id: 'send-to-front', keys: { key: ']' },
@@ -311,7 +453,9 @@ export const shortcuts: ShortcutDef[] = [
     handler: (ctx) => {
       const selected = ctx.selection.getSelectedItems();
       if (selected.length > 0) {
-        ctx.clipboardRef.current = [...selected];
+        // Include group children in clipboard for proper paste
+        ctx.clipboardRef.current = _collectGroupChildren(selected, ctx.scene);
+        markInternalCopy();
         ctx.writeCanvasToClipboard(selected);
         ctx.showToast('Copied');
       } else {
@@ -332,24 +476,36 @@ export const shortcuts: ShortcutDef[] = [
     id: 'paste', keys: { key: 'v', ctrl: true },
     category: 'editing', description: 'Paste',
     handler: async (ctx) => {
-      if (ctx.clipboardRef.current.length === 0) return;
+      // Strategy: Check system clipboard for images first.
-      const newItems: typeof ctx.clipboardRef.current = [];
+      // - If system clipboard has an image AND we did NOT just do an internal copy
-      for (const original of ctx.clipboardRef.current) {
+      //   (or it's been a while), paste from system clipboard (external image).
-        // Clone: duplicate the item data with new ID and offset position
+      // - If we just did an internal copy (lastInternalCopyTime is recent),
-        const newData = {
+      //   use internal clipboard to duplicate scene items (preserves vector data).
-          ...original.data,
+      // - If system clipboard has no images, fall back to internal clipboard.
-          id: crypto.randomUUID(),
+
-          x: original.data.x + 20,
+      const timeSinceInternalCopy = Date.now() - _lastInternalCopyTime;
-          y: original.data.y + 20,
+      const hasInternalItems = ctx.clipboardRef.current.length > 0;
-          z: ctx.scene.nextZ(),
+      const recentInternalCopy = hasInternalItems && timeSinceInternalCopy < 500;
-        };
+
-        await ctx.scene._createItem(newData, true);
+      // If we JUST did an internal copy (<500ms ago), use internal clipboard
-        const newItem = ctx.scene.getById(newData.id);
+      // (the system clipboard image is just the rasterized version of what we copied)
-        if (newItem) newItems.push(newItem);
+      if (recentInternalCopy) {
+        await _pasteInternal(ctx);
+        return;
+      }
+
+      // Try system clipboard first
+      try {
+        const result = await ctx.pasteFromSystemClipboard();
+        if (result === 'Pasted image') return;
+      } catch {
+        // Clipboard API denied or unavailable — fall through
+      }
+
+      // Fall back to internal clipboard
+      if (hasInternalItems) {
+        await _pasteInternal(ctx);
       }
-      ctx.clipboardRef.current = newItems;
-      ctx.scene._applyZOrder();
-      ctx.onChange();
     },
   },
   {
@@ -358,7 +514,8 @@ export const shortcuts: ShortcutDef[] = [
     handler: (ctx) => {
       const selected = ctx.selection.getSelectedItems();
       if (selected.length === 0) return;
-      ctx.clipboardRef.current = [...selected];
+      ctx.clipboardRef.current = _collectGroupChildren(selected, ctx.scene);
+      markInternalCopy();
       ctx.writeCanvasToClipboard(selected);
       for (const item of selected) {
         ctx.scene.removeItem(item.id, true);
@@ -374,14 +531,13 @@ export const shortcuts: ShortcutDef[] = [
     handler: async (ctx) => {
       const selected = ctx.selection.getSelectedItems();
       if (selected.length === 0) return;
-      for (const original of selected) {
+
-        const newData = {
+      // Collect group children and clone with remapped IDs
-          ...original.data,
+      const allItems = _collectGroupChildren(selected, ctx.scene);
-          id: crypto.randomUUID(),
+      const clones = _cloneItemsWithOffset(allItems, ctx.scene);
-          x: original.data.x + 20,
+      const sorted = [...clones].sort((a: any, b: any) =>
-          y: original.data.y + 20,
+        (a.type === 'group' ? 1 : 0) - (b.type === 'group' ? 1 : 0));
-          z: ctx.scene.nextZ(),
+      for (const newData of sorted) {
-        };
         await ctx.scene._createItem(newData, true);
       }
       ctx.selection.clear();
@@ -455,6 +611,27 @@ export const shortcuts: ShortcutDef[] = [
     category: 'editing', description: 'Ungroup', needsSelection: true,
     handler: (ctx) => ctx.handleUngroup(),
   },
+  // Opacity: [ and ] with Alt
+  {
+    id: 'opacity-down', keys: { key: '[', alt: true },
+    category: 'image', description: 'Decrease opacity 10%', needsSelection: true,
+    handler: (ctx) => {
+      const items = ctx.selection.getSelectedItems();
+      const current = items[0]?.data.opacity ?? 1;
+      ops.setOpacity(items, Math.max(0.1, current - 0.1));
+      ctx.onChange();
+    },
+  },
+  {
+    id: 'opacity-up', keys: { key: ']', alt: true },
+    category: 'image', description: 'Increase opacity 10%', needsSelection: true,
+    handler: (ctx) => {
+      const items = ctx.selection.getSelectedItems();
+      const current = items[0]?.data.opacity ?? 1;
+      ops.setOpacity(items, Math.min(1, current + 0.1));
+      ctx.onChange();
+    },
+  },
   // Block Ctrl+S from opening browser save-as dialog
   {
     id: 'save', keys: { key: 's', ctrl: true },

frontend/src/canvas/shortcuts.ts

@@ -43,7 +43,10 @@ export interface ShortcutContext {
   handleUngroup: () => void;
   toggleGrid: () => void;
   toggleShowHelp: () => void;
+  toggleFocusMode: () => void;
+  fitSelection: () => void;
   writeCanvasToClipboard: (items?: SceneItem[]) => Promise<void>;
+  pasteFromSystemClipboard: () => Promise<string>;
 }
 
 /**

frontend/src/canvas/sprites/DrawingSprite.ts

@@ -0,0 +1,91 @@
+import { Graphics } from 'pixi.js';
+
+/**
+ * DrawingSprite — renders a freehand stroke from a flat points array.
+ * Points stored as [x0, y0, x1, y1, ...] relative to the item's origin.
+ *
+ * Uses batched redraw during live drawing — accumulates points and redraws
+ * on the next animation frame. This avoids expensive per-pointermove redraws
+ * while keeping the stroke visually smooth.
+ */
+export class DrawingSprite extends Graphics {
+  private _points: number[] = [];
+  private _color: string;
+  private _strokeWidth: number;
+  private _rafId: number | null = null;
+  private _dirty = false;
+
+  constructor(points: number[], color: string, strokeWidth: number) {
+    super();
+    this._points = points;
+    this._color = color;
+    this._strokeWidth = strokeWidth;
+    this._redraw();
+  }
+
+  get points(): number[] {
+    return this._points;
+  }
+
+  /** Append a point during live drawing — batches redraw to next rAF. */
+  addPoint(x: number, y: number): void {
+    this._points.push(x, y);
+    if (!this._dirty) {
+      this._dirty = true;
+      this._rafId = requestAnimationFrame(() => {
+        this._rafId = null;
+        this._dirty = false;
+        this._redraw();
+      });
+    }
+  }
+
+  /** Replace all points and redraw immediately. Used for scene load / sync. */
+  setPoints(pts: number[]): void {
+    this._points = pts;
+    if (this._rafId !== null) {
+      cancelAnimationFrame(this._rafId);
+      this._rafId = null;
+      this._dirty = false;
+    }
+    this._redraw();
+  }
+
+  private _redraw(): void {
+    this.clear();
+    const pts = this._points;
+    if (pts.length < 4) return;
+
+    this.setStrokeStyle({
+      width: this._strokeWidth,
+      color: this._color,
+      cap: 'round',
+      join: 'round',
+    });
+
+    this.moveTo(pts[0], pts[1]);
+
+    // Use quadratic curve smoothing for 3+ points
+    if (pts.length >= 6) {
+      for (let i = 2; i < pts.length - 2; i += 2) {
+        const mx = (pts[i] + pts[i + 2]) / 2;
+        const my = (pts[i + 1] + pts[i + 3]) / 2;
+        this.quadraticCurveTo(pts[i], pts[i + 1], mx, my);
+      }
+      // Last segment
+      this.lineTo(pts[pts.length - 2], pts[pts.length - 1]);
+    } else {
+      this.lineTo(pts[2], pts[3]);
+    }
+
+    this.stroke();
+  }
+
+  override destroy(options?: any): void {
+    if (this._rafId !== null) {
+      cancelAnimationFrame(this._rafId);
+      this._rafId = null;
+    }
+    super.destroy(options);
+  }
+}

frontend/src/canvas/sprites/FrameSprite.ts

@@ -0,0 +1,146 @@
+/**
+ * FrameSprite — visual container for groups/frames.
+ *
+ * Renders as a colored BORDER (not fill) with rounded corners + title label.
+ * Extends Container. The border and label are the first children,
+ * so actual group children render on top.
+ * Lightweight: one Graphics rect + one Text. No filters or shaders.
+ */
+
+import { Container, Graphics, Text, TextStyle } from 'pixi.js';
+import type { GroupObject } from '../scene-format';
+
+const DEFAULT_PADDING = 16;
+const LABEL_FONT_SIZE = 11;
+const BORDER_WIDTH = 2;
+const CORNER_RADIUS = 6;
+
+const FRAME_COLORS = [
+  '#4a90d9', '#69db7c', '#ff6b6b', '#7950f2', '#38d9a9',
+  '#ffa94d', '#e64980', '#20c997', '#4dabf7', '#ffd43b',
+];
+
+/** Pick a random frame color for new groups. */
+export function randomFrameColor(): string {
+  return FRAME_COLORS[Math.floor(Math.random() * FRAME_COLORS.length)];
+}
+
+export class FrameSprite extends Container {
+  private _bg: Graphics;
+  private _label: Text;
+  private _labelBg: Graphics;
+  private _bgColor: string;
+  private _padding: number;
+  private _frameW: number;
+  private _frameH: number;
+  private _labelText: string;
+
+  constructor(w: number, h: number, bgColor?: string, label?: string, padding?: number) {
+    super();
+
+    this._bgColor = bgColor || '';
+    this._padding = padding ?? DEFAULT_PADDING;
+    this._frameW = w;
+    this._frameH = h;
+    this._labelText = label || '';
+
+    // Border rect (drawn first = behind everything)
+    this._bg = new Graphics();
+    this._bg.label = '__frame_bg';
+    this.addChild(this._bg);
+
+    // Label background pill
+    this._labelBg = new Graphics();
+    this._labelBg.label = '__frame_labelbg';
+    this.addChild(this._labelBg);
+
+    // Title label
+    this._label = new Text({
+      text: this._labelText,
+      style: new TextStyle({
+        fontSize: LABEL_FONT_SIZE,
+        fontFamily: 'system-ui, -apple-system, sans-serif',
+        fill: '#ffffff',
+        fontWeight: '600',
+      }),
+    });
+    this._label.label = '__frame_label';
+    this.addChild(this._label);
+
+    this._redraw();
+  }
+
+  get bgColor(): string { return this._bgColor; }
+  get padding(): number { return this._padding; }
+
+  setBgColor(color: string): void {
+    this._bgColor = color;
+    this._redraw();
+  }
+
+  setLabel(text: string): void {
+    this._labelText = text;
+    this._label.text = text;
+    this._redraw();
+  }
+
+  /** Update frame dimensions (call after children bounds change). */
+  setFrameSize(w: number, h: number): void {
+    this._frameW = w;
+    this._frameH = h;
+    this._redraw();
+  }
+
+  /** Update from GroupObject data. */
+  updateFromData(data: GroupObject): void {
+    this._bgColor = data.bgColor || '';
+    this._labelText = data.label || '';
+    this._padding = data.padding ?? DEFAULT_PADDING;
+    this._frameW = data.w;
+    this._frameH = data.h;
+    this._label.text = this._labelText;
+    this._redraw();
+  }
+
+  private _redraw(): void {
+    this._bg.clear();
+    this._labelBg.clear();
+
+    if (!this._bgColor) {
+      this._bg.visible = false;
+      this._labelBg.visible = false;
+      this._label.visible = false;
+      return;
+    }
+
+    this._bg.visible = true;
+    const pad = this._padding;
+    const color = parseInt(this._bgColor.replace('#', ''), 16);
+
+    // Draw border-only rounded rect (no fill, just stroke)
+    this._bg.roundRect(-pad, -pad, this._frameW + pad * 2, this._frameH + pad * 2, CORNER_RADIUS);
+    this._bg.stroke({
+      color,
+      alpha: 0.6,
+      width: BORDER_WIDTH,
+    });
+
+    // Label positioned at top-left corner, overlapping the border
+    const hasLabel = this._labelText.length > 0;
+    this._label.visible = hasLabel;
+    this._labelBg.visible = hasLabel;
+
+    if (hasLabel) {
+      const lx = -pad;
+      const ly = -pad - LABEL_FONT_SIZE - 6;
+
+      this._label.position.set(lx + 8, ly + 3);
+
+      // Background pill behind label text
+      const lw = this._label.width + 16;
+      const lh = LABEL_FONT_SIZE + 6;
+      this._labelBg.roundRect(lx, ly, lw, lh, CORNER_RADIUS);
+      this._labelBg.fill({ color, alpha: 0.8 });
+    }
+  }
+}

frontend/src/canvas/sprites/ImageSprite.ts

@@ -1,25 +1,24 @@
-import { Sprite, Texture, Graphics } from "pixi.js";
+import { Container, Sprite, Texture, Graphics } from "pixi.js";
-import { DropShadowFilter } from "pixi-filters";
+import { TextureManager } from "../TextureManager";
-import { TextureManager, LODTier } from "../TextureManager";
 
 /**
- * A Sprite subclass that manages LOD tier switching and lazy loading.
+ * A Container holding a shadow graphic + sprite with lazy texture loading.
- * Shows a placeholder shimmer rect until the first texture tier loads,
+ * Uses a lightweight Graphics shadow instead of DropShadowFilter (GPU-heavy).
- * then swaps textures as zoom level changes.
  */
 // Shadow defaults (resting state)
-const SHADOW_REST = { offsetX: 3, offsetY: 3, blur: 4, alpha: 0.25 };
+const SHADOW_REST = { offsetX: 3, offsetY: 3, alpha: 0.2 };
 // Shadow lifted state (during drag)
-const SHADOW_LIFT = { offsetX: 6, offsetY: 8, blur: 8, alpha: 0.35 };
+const SHADOW_LIFT = { offsetX: 6, offsetY: 8, alpha: 0.3 };
 
-export class ImageSprite extends Sprite {
+export class ImageSprite extends Container {
   readonly assetKey: string;
-  readonly shadow: DropShadowFilter;
 
   private textures: TextureManager;
-  private currentTier: LODTier | null = null;
+  private loaded = false;
   private loading = false;
   private placeholder: Graphics | null = null;
+  private _sprite: Sprite;
+  private _shadow: Graphics;
   private _naturalWidth: number;
   private _naturalHeight: number;
 
@@ -29,24 +28,23 @@ export class ImageSprite extends Sprite {
     h: number,
     textures: TextureManager,
   ) {
-    super(Texture.EMPTY);
+    super();
 
     this.assetKey = assetKey;
     this.textures = textures;
     this._naturalWidth = w;
     this._naturalHeight = h;
 
-    this.width = w;
+    // Shadow: simple dark rect behind the sprite (cheap, no GPU filter)
-    this.height = h;
+    this._shadow = new Graphics();
+    this._drawShadow(SHADOW_REST);
+    this.addChild(this._shadow);
 
-    // Drop shadow for photos-on-a-desk feel
+    // Main sprite
-    this.shadow = new DropShadowFilter({
+    this._sprite = new Sprite(Texture.EMPTY);
-      offset: { x: SHADOW_REST.offsetX, y: SHADOW_REST.offsetY },
+    this._sprite.width = w;
-      blur: SHADOW_REST.blur,
+    this._sprite.height = h;
-      alpha: SHADOW_REST.alpha,
+    this.addChild(this._sprite);
-      color: 0x000000,
-    });
-    this.filters = [this.shadow];
 
     // Create placeholder: dark rect shown until first texture loads
     const placeholder = new Graphics();
@@ -54,40 +52,39 @@ export class ImageSprite extends Sprite {
     this.placeholder = placeholder;
     this.addChild(placeholder);
 
-    // Immediately start loading the thumbnail tier
+    // Immediately start loading the full texture
-    this.loadTier("thumb");
+    this.loadTexture();
+  }
+
+  private _drawShadow(cfg: { offsetX: number; offsetY: number; alpha: number }): void {
+    this._shadow.clear();
+    this._shadow.rect(cfg.offsetX, cfg.offsetY, this._naturalWidth, this._naturalHeight);
+    this._shadow.fill({ color: 0x000000, alpha: cfg.alpha });
   }
 
   /** Expand shadow for drag-lift effect. */
   liftShadow(): void {
-    this.shadow.offset = { x: SHADOW_LIFT.offsetX, y: SHADOW_LIFT.offsetY };
+    this._drawShadow(SHADOW_LIFT);
-    this.shadow.blur = SHADOW_LIFT.blur;
-    this.shadow.alpha = SHADOW_LIFT.alpha;
   }
 
   /** Restore shadow to resting state. */
   dropShadow(): void {
-    this.shadow.offset = { x: SHADOW_REST.offsetX, y: SHADOW_REST.offsetY };
+    this._drawShadow(SHADOW_REST);
-    this.shadow.blur = SHADOW_REST.blur;
-    this.shadow.alpha = SHADOW_REST.alpha;
   }
 
-  /**
+  /** Load the full-res texture. GPU handles scaling natively. */
-   * Load a specific LOD tier texture for this sprite.
+  async loadTexture(): Promise<void> {
-   * Skips if already at the requested tier or currently loading.
+    if (this.loaded || this.loading) return;
-   */
-  async loadTier(tier: LODTier): Promise<void> {
-    if (this.currentTier === tier || this.loading) return;
 
     this.loading = true;
     try {
-      const tex = await this.textures.load(this.assetKey, tier);
+      const tex = await this.textures.load(this.assetKey);
-      this.texture = tex;
+      this._sprite.texture = tex;
-      this.width = this._naturalWidth;
+      this._sprite.width = this._naturalWidth;
-      this.height = this._naturalHeight;
+      this._sprite.height = this._naturalHeight;
-      this.currentTier = tier;
+      this.loaded = true;
 
-      // Remove placeholder after first successful load
+      // Remove placeholder after successful load
       if (this.placeholder) {
         this.removeChild(this.placeholder);
         this.placeholder.destroy();
@@ -95,29 +92,11 @@ export class ImageSprite extends Sprite {
       }
     } catch (err) {
       console.warn(
-        `[ImageSprite] Failed to load tier "${tier}" for "${this.assetKey}":`,
+        `[ImageSprite] Failed to load "${this.assetKey}":`,
         err,
       );
     } finally {
       this.loading = false;
     }
   }
-
-  /**
-   * Evaluate the current zoom level and switch LOD tier if needed.
-   */
-  updateLOD(zoom: number): void {
-    const needed = this.textures.tierForZoom(zoom);
-    if (needed !== this.currentTier) {
-      this.loadTier(needed);
-    }
-  }
-
-  /**
-   * Release the current texture (for off-screen sprites to free GPU memory).
-   */
-  unloadTexture(): void {
-    this.texture = Texture.EMPTY;
-    this.currentTier = null;
-  }
 }

frontend/src/canvas/sync.ts

@@ -1,47 +1,128 @@
 import type { Socket } from 'socket.io-client';
 import type { SceneManager, SceneItem } from './SceneManager';
-import type { SceneData } from './scene-format';
+import type { SceneData, AnySceneObject } from './scene-format';
 
 /**
- * Full-scene sync (v2 format, PixiJS / SceneManager):
+ * Sync protocol v3 — Excalidraw-inspired incremental element sync.
  *
- * 1. On any change → broadcast serialized SceneData (throttled 300ms)
+ * Three event tiers:
- * 2. On receive → sceneManager.loadScene() (diff-based, no flicker)
+ *   1. scene:update   — full scene snapshot. Sent on join (INIT) and periodically
- * 3. During drag → lightweight transform events (throttled 50ms)
+ *      to correct any drift. Receiver does full reconciliation via loadScene().
+ *   2. element:update  — array of changed elements only. Sent on any element
+ *      change (add, modify, draw). Receiver merges incrementally — no full scene
+ *      diff needed. Each element carries a `_v` version; receiver skips stale.
+ *   3. element:remove  — array of removed element IDs. Receiver deletes them.
+ *   4. object:transform — ephemeral position/scale during drag (unchanged).
  *
- * Diff-based loading doesn't trigger change events for unchanged objects,
+ * During freehand drawing, only the single drawing element is sent via
- * so no suppress/resume logic is needed.
+ * element:update every ~60ms (one frame) — tiny payload, no lag.
  */
 
+export interface SyncHandle {
+  cleanup: () => void;
+  broadcastTransform: (item: SceneItem) => void;
+  /** Force an immediate full scene broadcast (call after structural changes). */
+  broadcastSceneNow: () => void;
+  /** Broadcast only specific changed elements (lightweight). */
+  broadcastElements: (ids: string[]) => void;
+}
+
+export interface SyncOptions {
+  onRemoteTransform?: (item: SceneItem) => void;
+}
+
 export function setupSync(
   sceneManager: SceneManager,
   socket: Socket,
   boardId: string,
-): () => void {
+  options?: SyncOptions,
-  let sceneTimer: ReturnType<typeof setTimeout> | null = null;
+): SyncHandle {
+  let debounceTimer: ReturnType<typeof setTimeout> | null = null;
   let moveTimer: ReturnType<typeof setTimeout> | null = null;
-  let receiving = false; // true while applying a remote scene/transform
+  let receiving = false;
-  const SCENE_THROTTLE = 300; // ms
+  let localVersion = 0;
-  const MOVE_THROTTLE = 50; // ms
+  let remoteVersion = 0;
+  const DEBOUNCE_MS = 500;
+  const MOVE_THROTTLE = 50;
 
-  // ---- BROADCAST: full scene (throttled) --------------------------------
+  // Track broadcasted element versions (like Excalidraw's broadcastedElementVersions)
+  const broadcastedVersions: Map<string, number> = new Map();
 
-  function broadcastScene() {
+  // Per-element version counter — bumped whenever an element changes locally
-    if (receiving) return;
+  const elementVersions: Map<string, number> = new Map();
-    if (sceneTimer) clearTimeout(sceneTimer);
+
-    sceneTimer = setTimeout(() => {
+  function bumpElementVersion(id: string): number {
-      sceneTimer = null;
+    const v = (elementVersions.get(id) ?? 0) + 1;
-      if (receiving) return;
+    elementVersions.set(id, v);
-      const scene = sceneManager.serialize();
+    return v;
-      socket.emit('scene:update', { boardId, scene });
-    }, SCENE_THROTTLE);
   }
 
-  // ---- BROADCAST: lightweight transform during drag ---------------------
+  // ---- BROADCAST: incremental element update --------------------------------
+
+  /** Send only the specified elements. Skips if element hasn't changed since last broadcast. */
+  function broadcastElements(ids: string[]) {
+    if (receiving) return;
+
+    const elements: (AnySceneObject & { _v: number })[] = [];
+    for (const id of ids) {
+      const item = sceneManager.getById(id);
+      if (!item) continue;
+
+      const v = elementVersions.get(id) ?? 0;
+      const lastBroadcasted = broadcastedVersions.get(id) ?? -1;
+      if (v <= lastBroadcasted) continue;
+
+      elements.push({ ...item.data, _v: v });
+      broadcastedVersions.set(id, v);
+    }
+
+    if (elements.length === 0) return;
+    socket.emit('element:update', { boardId, elements });
+  }
+
+  /** Broadcast all elements that changed since last broadcast. */
+  function broadcastChangedElements() {
+    if (receiving) return;
+    const ids: string[] = [];
+    for (const [id, v] of elementVersions) {
+      if (v > (broadcastedVersions.get(id) ?? -1)) {
+        ids.push(id);
+      }
+    }
+    if (ids.length > 0) broadcastElements(ids);
+  }
+
+  // ---- BROADCAST: full scene (for INIT / periodic resync) -------------------
+
+  function broadcastSceneNow() {
+    if (receiving) return;
+    if (debounceTimer) { clearTimeout(debounceTimer); debounceTimer = null; }
+    localVersion++;
+    const scene = sceneManager.serialize();
+
+    // Update all broadcasted versions
+    for (const obj of scene.objects) {
+      const v = elementVersions.get(obj.id) ?? 0;
+      broadcastedVersions.set(obj.id, v);
+    }
+
+    socket.emit('scene:update', { boardId, scene, version: localVersion });
+  }
+
+  function broadcastSceneDebounced() {
+    if (receiving) return;
+    if (debounceTimer) clearTimeout(debounceTimer);
+    debounceTimer = setTimeout(() => {
+      debounceTimer = null;
+      broadcastSceneNow();
+    }, DEBOUNCE_MS);
+  }
+
+  // ---- BROADCAST: lightweight transform during drag -------------------------
 
   function broadcastTransform(item: SceneItem) {
     if (receiving) return;
-    if (moveTimer) return; // throttled
+    if (moveTimer) return;
     const { id, data } = item;
     socket.emit('object:transform', {
       boardId,
@@ -52,22 +133,34 @@ export function setupSync(
       sy: data.sy,
       angle: data.angle,
     });
-    moveTimer = setTimeout(() => {
+    moveTimer = setTimeout(() => { moveTimer = null; }, MOVE_THROTTLE);
-      moveTimer = null;
+    broadcastSceneDebounced();
-    }, MOVE_THROTTLE);
   }
 
-  // ---- RECEIVE: full scene ----------------------------------------------
+  // ---- RECEIVE: full scene --------------------------------------------------
 
   function onSceneReceived(payload: any) {
     if (payload.boardId !== boardId) return;
     const scene: SceneData = payload.scene;
     if (!scene || scene.v !== 2) return;
 
+    const incomingVersion = payload.version ?? 0;
+    if (incomingVersion > 0 && incomingVersion <= remoteVersion) return;
+    remoteVersion = incomingVersion;
+    if (incomingVersion >= localVersion) localVersion = incomingVersion;
+
     receiving = true;
     sceneManager
       .loadScene(scene)
       .then(() => {
+        // Update element versions from received data
+        for (const obj of scene.objects) {
+          const v = (obj as any)._v;
+          if (typeof v === 'number') {
+            const current = elementVersions.get(obj.id) ?? 0;
+            if (v > current) elementVersions.set(obj.id, v);
+          }
+        }
         receiving = false;
       })
       .catch((err: any) => {
@@ -76,42 +169,91 @@ export function setupSync(
       });
   }
 
-  // ---- RECEIVE: lightweight transform -----------------------------------
+  // ---- RECEIVE: incremental element update ----------------------------------
+
+  function onElementUpdate(payload: any) {
+    if (payload.boardId !== boardId) return;
+    const elements: (AnySceneObject & { _v?: number })[] = payload.elements;
+    if (!Array.isArray(elements) || elements.length === 0) return;
+
+    for (const data of elements) {
+      const incomingV = data._v ?? 0;
+
+      // Clean the _v field before storing
+      const cleanData = { ...data };
+      delete (cleanData as any)._v;
+
+      const existing = sceneManager.getById(data.id);
+      if (existing) {
+        // Update existing — apply incremental merge
+        sceneManager._updateItem(existing, cleanData);
+      } else {
+        // New element — create it
+        sceneManager._createItem(cleanData, false);
+      }
+
+      // Track the version
+      if (incomingV > 0) {
+        const current = elementVersions.get(data.id) ?? 0;
+        if (incomingV > current) elementVersions.set(data.id, incomingV);
+      }
+    }
+
+    sceneManager._applyZOrder();
+  }
+
+  // ---- RECEIVE: element removal ---------------------------------------------
+
+  function onElementRemove(payload: any) {
+    if (payload.boardId !== boardId) return;
+    const ids: string[] = payload.ids;
+    if (!Array.isArray(ids)) return;
+    for (const id of ids) {
+      sceneManager.removeItem(id, true);
+      elementVersions.delete(id);
+      broadcastedVersions.delete(id);
+    }
+  }
+
+  // ---- RECEIVE: lightweight transform ---------------------------------------
 
   function onTransformReceived(payload: any) {
     if (payload.boardId !== boardId) return;
     const item = sceneManager.getById(payload.objectId);
     if (!item) return;
 
-    // Update data model
     item.data.x = payload.x;
     item.data.y = payload.y;
     item.data.sx = payload.sx;
     item.data.sy = payload.sy;
     item.data.angle = payload.angle;
 
-    // Update display object
     const obj = item.displayObject;
     obj.position.set(payload.x, payload.y);
     obj.scale.set(payload.sx, payload.sy);
     obj.angle = payload.angle;
-    // No onChange — this is a remote update
+
+    options?.onRemoteTransform?.(item);
   }
 
-  // ---- Wire up SceneManager onChange → broadcastScene --------------------
+  // ---- Wire up SceneManager onChange → debounced full sync -------------------
 
   const prevOnChange = sceneManager.onChange;
   sceneManager.onChange = () => {
     prevOnChange?.();
-    broadcastScene();
+    // Structural change — schedule a full scene sync (debounced).
+    // Incremental element sync is handled explicitly by tools via broadcastElements().
+    broadcastSceneDebounced();
   };
 
-  // ---- Bind socket events -----------------------------------------------
+  // ---- Bind socket events ---------------------------------------------------
 
   socket.on('scene:update', onSceneReceived);
+  socket.on('element:update', onElementUpdate);
+  socket.on('element:remove', onElementRemove);
   socket.on('object:transform', onTransformReceived);
 
-  // ---- Join room --------------------------------------------------------
+  // ---- Join room ------------------------------------------------------------
 
   socket.emit('board:join', { boardId }, (response: any) => {
     if (response?.users) {
@@ -119,21 +261,24 @@ export function setupSync(
     }
   });
 
-  // ---- Cleanup ----------------------------------------------------------
+  // ---- Return handle --------------------------------------------------------
 
-  return () => {
+  return {
-    // Restore previous onChange
+    broadcastTransform,
-    sceneManager.onChange = prevOnChange;
+    broadcastSceneNow,
-
+    broadcastElements(ids: string[]) {
-    socket.off('scene:update', onSceneReceived);
+      for (const id of ids) bumpElementVersion(id);
-    socket.off('object:transform', onTransformReceived);
+      broadcastElements(ids);
-
+    },
-    socket.emit('board:leave', { boardId });
+    cleanup: () => {
-
+      sceneManager.onChange = prevOnChange;
-    if (sceneTimer) clearTimeout(sceneTimer);
+      socket.off('scene:update', onSceneReceived);
-    if (moveTimer) clearTimeout(moveTimer);
+      socket.off('element:update', onElementUpdate);
+      socket.off('element:remove', onElementRemove);
+      socket.off('object:transform', onTransformReceived);
+      socket.emit('board:leave', { boardId });
+      if (debounceTimer) clearTimeout(debounceTimer);
+      if (moveTimer) clearTimeout(moveTimer);
+    },
   };
 }
-
-// Note: broadcastTransform for drag events will be wired via Editor integration.
-// SelectionManager / TransformBox will call it directly once connected.

frontend/src/canvas/tools.ts

@@ -11,6 +11,8 @@ import type { Viewport } from 'pixi-viewport';
 import type { SceneManager } from './SceneManager';
 import type { SelectionManager } from './SelectionManager';
 import { Text, TextStyle } from 'pixi.js';
+import { DrawingSprite } from './sprites/DrawingSprite';
+import type { DrawingObject } from './scene-format';
 
 export enum ToolType {
   SELECT = 'SELECT',
@@ -40,6 +42,8 @@ export interface ToolContext {
   selection: SelectionManager;
   container: HTMLElement;
   onChange: () => void;
+  /** Broadcast only specific changed elements (lightweight, for live drawing). */
+  broadcastElements?: (ids: string[]) => void;
 }
 
 export function activateTool(
@@ -53,6 +57,9 @@ export function activateTool(
   // Reset cursor
   container.style.cursor = '';
 
+  // Enable/disable SelectionManager based on tool
+  selection.setEnabled(tool === ToolType.SELECT);
+
   switch (tool) {
     case ToolType.SELECT: {
       container.style.cursor = 'default';
@@ -96,6 +103,7 @@ export function activateTool(
 
         scene._createItem(textData, true);
         scene._applyZOrder();
+        ctx.broadcastElements?.([textData.id]);
         ctx.onChange();
 
         // Remove handler after placing text
@@ -110,12 +118,17 @@ export function activateTool(
 
     case ToolType.ERASER: {
       container.style.cursor = 'crosshair';
+      // Clear any existing selection/transform box when switching to eraser
+      selection.clear();
+      selection.transformBox.update([]);
 
       const onClick = (e: PointerEvent) => {
         const rect = container.getBoundingClientRect();
         const world = viewport.toWorld(e.clientX - rect.left, e.clientY - rect.top);
         const hit = selection._hitTest(world.x, world.y);
         if (hit) {
+          selection.selectedIds.delete(hit.id);
+          selection.transformBox.update([]);
           scene.removeItem(hit.id, true);
           ctx.onChange();
         }
@@ -129,8 +142,131 @@ export function activateTool(
 
     case ToolType.PEN: {
       container.style.cursor = 'crosshair';
-      // Drawing mode stub — will be implemented later
+
-      return null;
+      let drawing = false;
+      let currentSprite: DrawingSprite | null = null;
+      let originX = 0;
+      let originY = 0;
+      let itemId = '';
+      let syncTimer: ReturnType<typeof setTimeout> | null = null;
+      const SYNC_INTERVAL = 100; // ~10fps — lightweight element-only sync
+
+      const scheduleLiveSync = () => {
+        if (syncTimer) return;
+        syncTimer = setTimeout(() => {
+          syncTimer = null;
+          if (!drawing) return;
+          // Copy current points into item.data for serialization
+          const item = scene.getById(itemId);
+          if (item && currentSprite) {
+            (item.data as DrawingObject).points = [...currentSprite.points];
+          }
+          // Send only the drawing element, not the entire scene
+          ctx.broadcastElements?.([itemId]);
+        }, SYNC_INTERVAL);
+      };
+
+      const onDown = (e: PointerEvent) => {
+        if (e.button !== 0) return;
+        drawing = true;
+        const rect = container.getBoundingClientRect();
+        const world = viewport.toWorld(e.clientX - rect.left, e.clientY - rect.top);
+        originX = world.x;
+        originY = world.y;
+
+        itemId = crypto.randomUUID();
+        const drawData: DrawingObject = {
+          id: itemId,
+          type: 'drawing',
+          x: originX,
+          y: originY,
+          w: 1,
+          h: 1,
+          sx: 1,
+          sy: 1,
+          angle: 0,
+          z: scene.nextZ(),
+          opacity: 1,
+          locked: false,
+          name: '',
+          visible: true,
+          points: [0, 0],
+          color: opts.color!,
+          strokeWidth: opts.strokeWidth!,
+        };
+
+        scene._createItem(drawData, false);
+        const item = scene.getById(itemId);
+        if (item && item.displayObject instanceof DrawingSprite) {
+          currentSprite = item.displayObject as DrawingSprite;
+        }
+        container.setPointerCapture(e.pointerId);
+      };
+
+      const onMove = (e: PointerEvent) => {
+        if (!drawing || !currentSprite) return;
+        const rect = container.getBoundingClientRect();
+        const world = viewport.toWorld(e.clientX - rect.left, e.clientY - rect.top);
+        currentSprite.addPoint(world.x - originX, world.y - originY);
+        scheduleLiveSync();
+      };
+
+      const onUp = () => {
+        if (!drawing) return;
+        drawing = false;
+        if (syncTimer) { clearTimeout(syncTimer); syncTimer = null; }
+
+        // Compute bounding box and normalize points so origin = top-left of stroke
+        const item = scene.getById(itemId);
+        if (item && currentSprite) {
+          const pts = currentSprite.points;
+          if (pts.length < 4) {
+            scene.removeItem(itemId, false);
+          } else {
+            // Find bounds of all points
+            let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+            for (let i = 0; i < pts.length; i += 2) {
+              minX = Math.min(minX, pts[i]);
+              minY = Math.min(minY, pts[i + 1]);
+              maxX = Math.max(maxX, pts[i]);
+              maxY = Math.max(maxY, pts[i + 1]);
+            }
+
+            const sw = opts.strokeWidth!;
+            // Shift all points so min = strokeWidth/2 (padding for stroke)
+            const normalized: number[] = [];
+            for (let i = 0; i < pts.length; i += 2) {
+              normalized.push(pts[i] - minX + sw / 2);
+              normalized.push(pts[i + 1] - minY + sw / 2);
+            }
+
+            // Update origin to account for the shift
+            item.data.x = originX + minX - sw / 2;
+            item.data.y = originY + minY - sw / 2;
+            item.data.w = Math.max(maxX - minX + sw, 1);
+            item.data.h = Math.max(maxY - minY + sw, 1);
+            (item.data as DrawingObject).points = normalized;
+
+            // Redraw with normalized points and reposition
+            currentSprite.setPoints(normalized);
+            item.displayObject.position.set(item.data.x, item.data.y);
+          }
+        }
+
+        currentSprite = null;
+        scene._applyZOrder();
+        ctx.onChange();
+      };
+
+      container.addEventListener('pointerdown', onDown);
+      container.addEventListener('pointermove', onMove);
+      container.addEventListener('pointerup', onUp);
+      return () => {
+        if (syncTimer) clearTimeout(syncTimer);
+        container.removeEventListener('pointerdown', onDown);
+        container.removeEventListener('pointermove', onMove);
+        container.removeEventListener('pointerup', onUp);
+      };
     }
 
     default:

frontend/src/components/Minimap.tsx

@@ -0,0 +1,199 @@
+import React, { useRef, useEffect, useCallback } from 'react';
+
+interface MinimapItem {
+  x: number;
+  y: number;
+  w: number;
+  h: number;
+  type: string;
+  id: string;
+}
+
+interface Bounds {
+  x: number;
+  y: number;
+  w: number;
+  h: number;
+}
+
+interface MinimapProps {
+  items: MinimapItem[];
+  viewportBounds: Bounds;   // world-space visible area
+  contentBounds: Bounds;    // world-space all-content bounds
+  onNavigate: (worldX: number, worldY: number) => void;
+}
+
+const MAP_W = 180;
+const MAP_H = 120;
+const PADDING_RATIO = 0.1;
+
+const TYPE_COLORS: Record<string, string> = {
+  image: '#4a9eff',
+  video: '#ff6b6b',
+  text: '#69db7c',
+  drawing: '#ffd43b',
+  group: '#7950f2',
+};
+
+function getColor(type: string): string {
+  return TYPE_COLORS[type] ?? '#888';
+}
+
+/** Compute the union of two bounding boxes. */
+function unionBounds(a: Bounds, b: Bounds): Bounds {
+  const x1 = Math.min(a.x, b.x);
+  const y1 = Math.min(a.y, b.y);
+  const x2 = Math.max(a.x + a.w, b.x + b.w);
+  const y2 = Math.max(a.y + a.h, b.y + b.h);
+  return { x: x1, y: y1, w: x2 - x1, h: y2 - y1 };
+}
+
+export default function Minimap({ items, viewportBounds, contentBounds, onNavigate }: MinimapProps) {
+  const canvasRef = useRef<HTMLCanvasElement>(null);
+  const draggingRef = useRef(false);
+  const rafRef = useRef<number | null>(null);
+
+  // Compute the mapping from world space to minimap pixel space.
+  // Returns { offsetX, offsetY, scale } so that:
+  //   minimapX = (worldX - offsetX) * scale
+  //   minimapY = (worldY - offsetY) * scale
+  const getMapping = useCallback(() => {
+    const scene = unionBounds(contentBounds, viewportBounds);
+
+    // Add 10% padding
+    const padX = scene.w * PADDING_RATIO;
+    const padY = scene.h * PADDING_RATIO;
+    const padded: Bounds = {
+      x: scene.x - padX,
+      y: scene.y - padY,
+      w: scene.w + padX * 2,
+      h: scene.h + padY * 2,
+    };
+
+    // Avoid division by zero
+    if (padded.w === 0 || padded.h === 0) {
+      return { offsetX: padded.x, offsetY: padded.y, scale: 1 };
+    }
+
+    const scale = Math.min(MAP_W / padded.w, MAP_H / padded.h);
+    return { offsetX: padded.x, offsetY: padded.y, scale };
+  }, [contentBounds, viewportBounds]);
+
+  // Convert minimap pixel coords to world coords
+  const minimapToWorld = useCallback((mx: number, my: number): { wx: number; wy: number } => {
+    const { offsetX, offsetY, scale } = getMapping();
+    return {
+      wx: mx / scale + offsetX,
+      wy: my / scale + offsetY,
+    };
+  }, [getMapping]);
+
+  // Handle pointer interaction (click / drag to navigate)
+  const handlePointerEvent = useCallback((e: React.PointerEvent<HTMLCanvasElement>) => {
+    e.stopPropagation();
+    e.preventDefault();
+    const canvas = canvasRef.current;
+    if (!canvas) return;
+    const rect = canvas.getBoundingClientRect();
+    const mx = e.clientX - rect.left;
+    const my = e.clientY - rect.top;
+    const { wx, wy } = minimapToWorld(mx, my);
+    onNavigate(wx, wy);
+  }, [minimapToWorld, onNavigate]);
+
+  const onPointerDown = useCallback((e: React.PointerEvent<HTMLCanvasElement>) => {
+    draggingRef.current = true;
+    (e.target as HTMLCanvasElement).setPointerCapture(e.pointerId);
+    handlePointerEvent(e);
+  }, [handlePointerEvent]);
+
+  const onPointerMove = useCallback((e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!draggingRef.current) return;
+    handlePointerEvent(e);
+  }, [handlePointerEvent]);
+
+  const onPointerUp = useCallback((e: React.PointerEvent<HTMLCanvasElement>) => {
+    draggingRef.current = false;
+    (e.target as HTMLCanvasElement).releasePointerCapture(e.pointerId);
+  }, []);
+
+  // Draw minimap
+  useEffect(() => {
+    if (rafRef.current !== null) {
+      cancelAnimationFrame(rafRef.current);
+    }
+
+    rafRef.current = requestAnimationFrame(() => {
+      rafRef.current = null;
+      const canvas = canvasRef.current;
+      if (!canvas) return;
+      const ctx = canvas.getContext('2d');
+      if (!ctx) return;
+
+      const dpr = window.devicePixelRatio || 1;
+      canvas.width = MAP_W * dpr;
+      canvas.height = MAP_H * dpr;
+      ctx.scale(dpr, dpr);
+
+      // Clear
+      ctx.clearRect(0, 0, MAP_W, MAP_H);
+
+      const { offsetX, offsetY, scale } = getMapping();
+
+      const toX = (wx: number) => (wx - offsetX) * scale;
+      const toY = (wy: number) => (wy - offsetY) * scale;
+
+      // Draw items
+      for (const item of items) {
+        const rx = toX(item.x);
+        const ry = toY(item.y);
+        const rw = Math.max(item.w * scale, 2);
+        const rh = Math.max(item.h * scale, 2);
+        ctx.fillStyle = getColor(item.type);
+        ctx.fillRect(rx, ry, rw, rh);
+      }
+
+      // Draw viewport frustum
+      const vx = toX(viewportBounds.x);
+      const vy = toY(viewportBounds.y);
+      const vw = viewportBounds.w * scale;
+      const vh = viewportBounds.h * scale;
+
+      ctx.fillStyle = 'rgba(255, 255, 255, 0.15)';
+      ctx.fillRect(vx, vy, vw, vh);
+
+      ctx.strokeStyle = '#ffffff';
+      ctx.lineWidth = 1;
+      ctx.strokeRect(vx + 0.5, vy + 0.5, vw, vh);
+    });
+
+    return () => {
+      if (rafRef.current !== null) {
+        cancelAnimationFrame(rafRef.current);
+        rafRef.current = null;
+      }
+    };
+  }, [items, viewportBounds, contentBounds, getMapping]);
+
+  return (
+    <canvas
+      ref={canvasRef}
+      style={{
+        position: 'fixed',
+        bottom: 12,
+        right: 12,
+        width: MAP_W,
+        height: MAP_H,
+        background: 'rgba(20, 20, 20, 0.9)',
+        border: '1px solid #333',
+        borderRadius: 8,
+        cursor: 'crosshair',
+        pointerEvents: 'auto',
+        zIndex: 100,
+      }}
+      onPointerDown={onPointerDown}
+      onPointerMove={onPointerMove}
+      onPointerUp={onPointerUp}
+    />
+  );
+}

frontend/src/components/SelectionToolbar.tsx

@@ -0,0 +1,200 @@
+import React from 'react';
+
+interface SelectionToolbarProps {
+  /** Screen-space position of the selection's top-center */
+  x: number;
+  y: number;
+  count: number;
+  onAlignLeft: () => void;
+  onAlignCenterH: () => void;
+  onAlignRight: () => void;
+  onAlignTop: () => void;
+  onAlignCenterV: () => void;
+  onAlignBottom: () => void;
+  onDistributeH: () => void;
+  onDistributeV: () => void;
+  onPack: () => void;
+  onGrid: () => void;
+  onRow: () => void;
+  onColumn: () => void;
+  onStack: () => void;
+  onFlipH: () => void;
+  onFlipV: () => void;
+  onGroup: () => void;
+  onNormSize: () => void;
+}
+
+// Tiny SVG icons for each action
+function IcoAlignL() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="2" y1="1" x2="2" y2="13" /><rect x="4" y="3" width="8" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="4" y="8" width="5" height="3" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoAlignCH() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="7" y1="1" x2="7" y2="13" strokeDasharray="1.5 1.5" /><rect x="2" y="3" width="10" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="3.5" y="8" width="7" height="3" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoAlignR() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="12" y1="1" x2="12" y2="13" /><rect x="2" y="3" width="8" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="5" y="8" width="5" height="3" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoAlignT() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="1" y1="2" x2="13" y2="2" /><rect x="3" y="4" width="3" height="8" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="8" y="4" width="3" height="5" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoAlignCV() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="1" y1="7" x2="13" y2="7" strokeDasharray="1.5 1.5" /><rect x="3" y="2" width="3" height="10" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="8" y="3.5" width="3" height="7" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoAlignB() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.4"><line x1="1" y1="12" x2="13" y2="12" /><rect x="3" y="2" width="3" height="8" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="8" y="5" width="3" height="5" rx="0.5" fill="currentColor" opacity="0.3" /></svg>;
+}
+function IcoDistH() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="3" width="3" height="8" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="5.5" y="3" width="3" height="8" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="10" y="3" width="3" height="8" rx="0.5" fill="currentColor" opacity="0.3" /><path d="M4.5 7h1M9 7h1" strokeWidth="1" /></svg>;
+}
+function IcoDistV() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="3" y="1" width="8" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="3" y="5.5" width="8" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><rect x="3" y="10" width="8" height="3" rx="0.5" fill="currentColor" opacity="0.3" /><path d="M7 4.5v1M7 9v1" strokeWidth="1" /></svg>;
+}
+function IcoPack() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="1" width="5" height="6" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="7" y="1" width="6" height="4" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="1" y="8" width="4" height="5" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="6" y="6" width="7" height="7" rx="0.5" fill="currentColor" opacity="0.2" /></svg>;
+}
+function IcoGrid() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="1" width="5" height="5" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="8" y="1" width="5" height="5" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="1" y="8" width="5" height="5" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="8" y="8" width="5" height="5" rx="0.5" fill="currentColor" opacity="0.2" /></svg>;
+}
+function IcoRow() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="4" width="3" height="6" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="5.5" y="4" width="3" height="6" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="10" y="4" width="3" height="6" rx="0.5" fill="currentColor" opacity="0.2" /></svg>;
+}
+function IcoCol() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="4" y="1" width="6" height="3" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="4" y="5.5" width="6" height="3" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="4" y="10" width="6" height="3" rx="0.5" fill="currentColor" opacity="0.2" /></svg>;
+}
+function IcoStack() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="2" y="2" width="10" height="10" rx="0.5" fill="currentColor" opacity="0.15" /><rect x="3" y="3" width="8" height="8" rx="0.5" fill="currentColor" opacity="0.15" /><rect x="4" y="4" width="6" height="6" rx="0.5" fill="currentColor" opacity="0.2" /></svg>;
+}
+function IcoFlipH() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.3"><line x1="7" y1="1" x2="7" y2="13" strokeDasharray="2 1" /><path d="M5 4H2L5 10V4Z" fill="currentColor" opacity="0.3" /><path d="M9 4H12L9 10V4Z" fill="currentColor" opacity="0.15" /></svg>;
+}
+function IcoFlipV() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.3"><line x1="1" y1="7" x2="13" y2="7" strokeDasharray="2 1" /><path d="M4 5V2L10 5H4Z" fill="currentColor" opacity="0.3" /><path d="M4 9V12L10 9H4Z" fill="currentColor" opacity="0.15" /></svg>;
+}
+function IcoGroup() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="1" width="12" height="12" rx="1.5" strokeDasharray="2 1.5" /><rect x="3" y="3" width="4" height="4" rx="0.5" fill="currentColor" opacity="0.25" /><rect x="7" y="7" width="4" height="4" rx="0.5" fill="currentColor" opacity="0.25" /></svg>;
+}
+function IcoNormSize() {
+  return <svg width="14" height="14" viewBox="0 0 14 14" fill="none" stroke="currentColor" strokeWidth="1.2"><rect x="1" y="4" width="5" height="8" rx="0.5" fill="currentColor" opacity="0.2" /><rect x="8" y="2" width="5" height="10" rx="0.5" fill="currentColor" opacity="0.2" /><path d="M3.5 1v2M10.5 1v2" strokeLinecap="round" /><line x1="3.5" y1="1.5" x2="10.5" y2="1.5" strokeLinecap="round" /></svg>;
+}
+
+interface BtnDef {
+  icon: React.FC;
+  label: string;
+  shortcut: string;
+  onClick: () => void;
+  minItems?: number;
+}
+
+export default function SelectionToolbar(props: SelectionToolbarProps) {
+  const { x, y, count } = props;
+
+  const groups: { label: string; items: BtnDef[] }[] = [
+    {
+      label: 'Align',
+      items: [
+        { icon: IcoAlignL, label: 'Align left', shortcut: 'Ctrl+\u2190', onClick: props.onAlignLeft },
+        { icon: IcoAlignCH, label: 'Align center H', shortcut: 'Ctrl+Alt+H', onClick: props.onAlignCenterH },
+        { icon: IcoAlignR, label: 'Align right', shortcut: 'Ctrl+\u2192', onClick: props.onAlignRight },
+        { icon: IcoAlignT, label: 'Align top', shortcut: 'Ctrl+\u2191', onClick: props.onAlignTop },
+        { icon: IcoAlignCV, label: 'Align center V', shortcut: 'Ctrl+Alt+V', onClick: props.onAlignCenterV },
+        { icon: IcoAlignB, label: 'Align bottom', shortcut: 'Ctrl+\u2193', onClick: props.onAlignBottom },
+      ],
+    },
+    {
+      label: 'Distribute',
+      items: [
+        { icon: IcoDistH, label: 'Distribute H', shortcut: 'Ctrl+Shift+H', onClick: props.onDistributeH, minItems: 3 },
+        { icon: IcoDistV, label: 'Distribute V', shortcut: 'Ctrl+Shift+V', onClick: props.onDistributeV, minItems: 3 },
+      ],
+    },
+    {
+      label: 'Arrange',
+      items: [
+        { icon: IcoPack, label: 'Pack', shortcut: 'Ctrl+Shift+P', onClick: props.onPack },
+        { icon: IcoGrid, label: 'Grid', shortcut: '', onClick: props.onGrid },
+        { icon: IcoRow, label: 'Row', shortcut: '', onClick: props.onRow },
+        { icon: IcoCol, label: 'Column', shortcut: '', onClick: props.onColumn },
+        { icon: IcoStack, label: 'Stack', shortcut: 'Ctrl+Alt+S', onClick: props.onStack },
+      ],
+    },
+    {
+      label: 'Transform',
+      items: [
+        { icon: IcoFlipH, label: 'Flip H', shortcut: 'Alt+Shift+H', onClick: props.onFlipH },
+        { icon: IcoFlipV, label: 'Flip V', shortcut: 'Alt+Shift+V', onClick: props.onFlipV },
+        { icon: IcoGroup, label: 'Group', shortcut: 'Ctrl+G', onClick: props.onGroup },
+        { icon: IcoNormSize, label: 'Same size', shortcut: '', onClick: props.onNormSize },
+      ],
+    },
+  ];
+
+  return (
+    <div
+      style={{
+        position: 'absolute',
+        left: x,
+        top: y - 8,
+        transform: 'translate(-50%, -100%)',
+        display: 'flex',
+        gap: '1px',
+        padding: '3px',
+        background: 'rgba(22, 22, 22, 0.96)',
+        border: '1px solid #333',
+        borderRadius: '10px',
+        backdropFilter: 'blur(12px)',
+        boxShadow: '0 4px 20px rgba(0,0,0,0.5)',
+        zIndex: 100,
+        pointerEvents: 'auto',
+      }}
+      onPointerDown={(e) => e.stopPropagation()}
+    >
+      {groups.map((group, gi) => (
+        <React.Fragment key={group.label}>
+          {gi > 0 && (
+            <div style={{ width: '1px', background: '#333', margin: '2px 2px', flexShrink: 0 }} />
+          )}
+          <div style={{ display: 'flex', gap: '1px' }}>
+            {group.items.map((btn) => {
+              const disabled = (btn.minItems ?? 2) > count;
+              const Icon = btn.icon;
+              return (
+                <button
+                  key={btn.label}
+                  onClick={btn.onClick}
+                  disabled={disabled}
+                  title={btn.shortcut ? `${btn.label} (${btn.shortcut})` : btn.label}
+                  style={{
+                    display: 'flex',
+                    alignItems: 'center',
+                    justifyContent: 'center',
+                    width: '26px',
+                    height: '26px',
+                    background: 'transparent',
+                    border: 'none',
+                    borderRadius: '5px',
+                    color: disabled ? '#444' : '#999',
+                    cursor: disabled ? 'default' : 'pointer',
+                    padding: 0,
+                    transition: 'all 0.1s',
+                  }}
+                  onMouseEnter={(e) => {
+                    if (!disabled) {
+                      e.currentTarget.style.background = '#333';
+                      e.currentTarget.style.color = '#fff';
+                    }
+                  }}
+                  onMouseLeave={(e) => {
+                    e.currentTarget.style.background = 'transparent';
+                    e.currentTarget.style.color = disabled ? '#444' : '#999';
+                  }}
+                >
+                  <Icon />
+                </button>
+              );
+            })}
+          </div>
+        </React.Fragment>
+      ))}
+    </div>
+  );
+}

frontend/src/components/Toolbar.tsx

@@ -26,6 +26,8 @@ interface ToolbarProps {
   onUndo: () => void;
   onRedo: () => void;
   onlineUsers: OnlineUser[];
+  onUserClick?: (userId: string, displayName: string) => void;
+  followingUserId?: string | null;
   onShareClick?: () => void;
   onToggleLayers?: () => void;
   showLayers?: boolean;
@@ -139,6 +141,8 @@ export default function Toolbar({
   onUndo,
   onRedo,
   onlineUsers,
+  onUserClick,
+  followingUserId,
   onShareClick,
   onToggleLayers,
   showLayers,
@@ -306,11 +310,16 @@ export default function Toolbar({
               background: `linear-gradient(135deg, ${u.color}, ${u.color}dd)`,
               display: 'flex', alignItems: 'center', justifyContent: 'center',
               fontSize: '10px', fontWeight: 700, color: '#fff',
-              border: '2px solid #1a1a1a',
+              border: followingUserId === u.userId ? '2px solid #4a9eff' : '2px solid #1a1a1a',
               marginLeft: i > 0 ? '-6px' : '0',
               zIndex: 5 - i,
-              boxShadow: '0 1px 3px rgba(0,0,0,0.3)',
+              boxShadow: followingUserId === u.userId ? '0 0 6px rgba(74,144,217,0.6)' : '0 1px 3px rgba(0,0,0,0.3)',
-            }}>
+              cursor: 'pointer',
+              transition: 'border-color 0.15s, box-shadow 0.15s',
+            }}
+            onClick={() => onUserClick?.(u.userId, u.displayName)}
+            title={`${u.displayName}${followingUserId === u.userId ? ' (following)' : ' — click to follow'}`}
+            >
               {(u.displayName || '?')[0].toUpperCase()}
             </div>
           ))}

frontend/src/components/UserCursors.tsx

@@ -91,10 +91,11 @@ export default function UserCursors({ socket, boardId, canvasTransform }: UserCu
             key={cursor.userId}
             style={{
               position: 'absolute',
-              left: screenX,
+              left: 0,
-              top: screenY,
+              top: 0,
-              transform: 'translate(-2px, -2px)',
+              transform: `translate(${screenX - 2}px, ${screenY - 2}px)`,
-              transition: 'left 0.1s, top 0.1s',
+              transition: 'transform 50ms linear',
+              willChange: 'transform',
             }}
           >
             <svg width="16" height="20" viewBox="0 0 16 20" fill="none">

frontend/src/hooks/useBoardLoader.ts

@@ -0,0 +1,44 @@
+import { useEffect, useState } from 'react';
+import { getBoard } from '../api';
+
+interface BoardLoaderResult {
+  boardData: any;
+  loading: boolean;
+  error: string;
+}
+
+/**
+ * Loads board data by ID with cancellation support.
+ */
+export function useBoardLoader(boardId: string | undefined): BoardLoaderResult {
+  const [boardData, setBoardData] = useState<any>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState('');
+
+  useEffect(() => {
+    let cancelled = false;
+    async function load() {
+      try {
+        if (!boardId) {
+          setError('No board specified');
+          setLoading(false);
+          return;
+        }
+        const res = await getBoard(boardId);
+        if (!cancelled) {
+          setBoardData(res.data);
+          setLoading(false);
+        }
+      } catch (err: any) {
+        if (!cancelled) {
+          setError(err.response?.data?.error || 'Failed to load board');
+          setLoading(false);
+        }
+      }
+    }
+    load();
+    return () => { cancelled = true; };
+  }, [boardId]);
+
+  return { boardData, loading, error };
+}

frontend/src/hooks/useCanvasSetup.ts

@@ -6,6 +6,8 @@ import { setupSync, SyncHandle } from '../canvas/sync';
 import { setupDragDrop, setupPaste } from '../canvas/image-drop';
 import { UndoManager } from '../canvas/history';
 import { InboxZone } from '../canvas/InboxZone';
+import { LaserPointer } from '../canvas/LaserPointer';
+// PresenceOverlay removed — remote selection highlighting was too heavy for minimal benefit
 import { connectSocket, disconnectSocket } from '../socket';
 
 interface OnlineUser {
@@ -57,6 +59,7 @@ export function useCanvasSetup(deps: CanvasSetupDeps) {
 
   const dropCleanupRef = useRef<(() => void) | null>(null);
   const pasteCleanupRef = useRef<(() => void) | null>(null);
+  const laserCleanupRef = useRef<(() => void) | null>(null);
 
   useEffect(() => {
     if (!boardData || !resolvedBoardId) return;
@@ -70,6 +73,9 @@ export function useCanvasSetup(deps: CanvasSetupDeps) {
       const selection = new SelectionManager(viewport, scene);
       selectionRef.current = selection;
 
+      // Wire snap guides to transform box
+      selection.transformBox.setSnapGuides(selection.snapGuides);
+
       // Wire selection change to update layer panel state
       selection.onSelectionChange = (ids: string[]) => {
         setSelectedLayerIds(ids);
@@ -176,6 +182,65 @@ export function useCanvasSetup(deps: CanvasSetupDeps) {
           cursorTimer = setTimeout(() => { cursorTimer = null; }, 33);
         };
         viewport.on('pointermove', onPointerMove);
+
+        // ---- Laser pointer (hold L key) ----
+        const laserColorHex = userColor(user?.id || '');
+        const laserColorNum = parseInt(laserColorHex.replace('#', ''), 16);
+        const laser = new LaserPointer(viewport, laserColorNum);
+
+        let laserTimer: ReturnType<typeof setTimeout> | null = null;
+        const onLaserMove = (e: any) => {
+          if (!laser.isActive) return;
+          const world = viewport.toWorld(e.global.x, e.global.y);
+          laser.addPoint(world.x, world.y);
+          // Throttle broadcast to ~50ms
+          if (laserTimer) return;
+          socket.volatile.emit('laser:move', {
+            boardId: resolvedBoardId,
+            points: [{ x: world.x, y: world.y }],
+          });
+          laserTimer = setTimeout(() => { laserTimer = null; }, 50);
+        };
+        viewport.on('pointermove', onLaserMove);
+
+        const onKeyDown = (e: KeyboardEvent) => {
+          if (e.key === 'l' || e.key === 'L') {
+            if (laser.isActive) return;
+            laser.start();
+          }
+        };
+        const onKeyUp = (e: KeyboardEvent) => {
+          if (e.key === 'l' || e.key === 'L') {
+            laser.stop();
+            socket.emit('laser:stop', { boardId: resolvedBoardId });
+          }
+        };
+        window.addEventListener('keydown', onKeyDown);
+        window.addEventListener('keyup', onKeyUp);
+
+        laserCleanupRef.current = () => {
+          window.removeEventListener('keydown', onKeyDown);
+          window.removeEventListener('keyup', onKeyUp);
+          laser.destroy();
+        };
+
+        // Listen for remote laser events
+        socket.on('laser:move', (data: any) => {
+          if (data.boardId !== resolvedBoardId) return;
+          const uid = data.userId;
+          if (!uid) return;
+          const color = parseInt(userColor(uid).replace('#', ''), 16);
+          laser.addRemotePoints(uid, data.points, color);
+        });
+        socket.on('laser:stop', (_data: any) => {
+          // Remote user stopped — points will fade naturally
+        });
+        socket.on('user:left', (data: any) => {
+          const uid = data.userId || data.id;
+          if (uid) {
+            laser.removeRemote(uid);
+          }
+        });
       }
 
       // Setup drag/drop and paste
@@ -208,6 +273,8 @@ export function useCanvasSetup(deps: CanvasSetupDeps) {
         inboxZoneRef.current = null;
       }
       syncRef.current?.cleanup();
+      laserCleanupRef.current?.();
+      laserCleanupRef.current = null;
       dropCleanupRef.current?.();
       pasteCleanupRef.current?.();
       disconnectSocket();

frontend/src/hooks/useFollowMode.ts

@@ -0,0 +1,127 @@
+import { useState, useEffect, useCallback, useRef } from 'react';
+import type { Socket } from 'socket.io-client';
+import type { Viewport } from 'pixi-viewport';
+
+interface FollowState {
+  followingUserId: string | null;
+  followingDisplayName: string | null;
+}
+
+interface UseFollowModeProps {
+  socket: Socket | null;
+  boardId: string | undefined;
+  getViewport: () => Viewport | null;
+}
+
+interface UseFollowModeReturn {
+  followingUserId: string | null;
+  followingDisplayName: string | null;
+  startFollowing: (userId: string, displayName: string) => void;
+  stopFollowing: () => void;
+}
+
+/**
+ * Follow mode — click a user's avatar to track their viewport in real-time.
+ * Broadcasts own viewport position so others can follow us.
+ * Pan/zoom manually to break free.
+ */
+export function useFollowMode({ socket, boardId, getViewport }: UseFollowModeProps): UseFollowModeReturn {
+  const [state, setState] = useState<FollowState>({
+    followingUserId: null,
+    followingDisplayName: null,
+  });
+  const followRef = useRef<string | null>(null);
+  const ignoreNextMove = useRef(false);
+
+  // Broadcast own viewport position (always, so others can follow us)
+  useEffect(() => {
+    if (!socket || !boardId) return;
+
+    const timer = setInterval(() => {
+      const vp = getViewport();
+      if (!vp) return;
+      socket.volatile.emit('viewport:sync', {
+        boardId,
+        x: vp.center.x,
+        y: vp.center.y,
+        scale: vp.scale.x,
+      });
+    }, 150);
+
+    return () => clearInterval(timer);
+  }, [socket, boardId, getViewport]);
+
+  // Listen for viewport:sync from followed user and animate to match
+  useEffect(() => {
+    if (!socket) return;
+
+    const onViewportSync = (data: { boardId: string; userId: string; x: number; y: number; scale: number }) => {
+      if (data.boardId !== boardId) return;
+      const targetId = followRef.current;
+      if (!targetId || data.userId !== targetId) return;
+
+      const vp = getViewport();
+      if (!vp) return;
+
+      ignoreNextMove.current = true;
+      vp.animate({
+        time: 200,
+        position: { x: data.x, y: data.y },
+        scale: data.scale,
+        ease: 'easeOutQuad',
+        callbackOnComplete: () => {
+          // Brief delay before re-enabling break-free detection
+          setTimeout(() => { ignoreNextMove.current = false; }, 50);
+        },
+      });
+    };
+
+    socket.on('viewport:sync', onViewportSync);
+    return () => { socket.off('viewport:sync', onViewportSync); };
+  }, [socket, boardId, getViewport]);
+
+  // Detect manual pan/zoom to break free from follow mode
+  useEffect(() => {
+    const vp = getViewport();
+    if (!vp) return;
+
+    const onMoved = () => {
+      if (ignoreNextMove.current) return;
+      if (followRef.current) {
+        followRef.current = null;
+        setState({ followingUserId: null, followingDisplayName: null });
+        socket?.emit('follow:stop', { boardId });
+      }
+    };
+
+    vp.on('moved-end', onMoved);
+    return () => { vp.off('moved-end', onMoved); };
+  }, [getViewport, socket, boardId]);
+
+  const startFollowing = useCallback((userId: string, displayName: string) => {
+    // Toggle: if already following this user, stop
+    if (followRef.current === userId) {
+      followRef.current = null;
+      setState({ followingUserId: null, followingDisplayName: null });
+      socket?.emit('follow:stop', { boardId });
+      return;
+    }
+
+    followRef.current = userId;
+    setState({ followingUserId: userId, followingDisplayName: displayName });
+    socket?.emit('follow:start', { boardId, targetUserId: userId });
+  }, [socket, boardId]);
+
+  const stopFollowing = useCallback(() => {
+    followRef.current = null;
+    setState({ followingUserId: null, followingDisplayName: null });
+    socket?.emit('follow:stop', { boardId });
+  }, [socket, boardId]);
+
+  return {
+    followingUserId: state.followingUserId,
+    followingDisplayName: state.followingDisplayName,
+    startFollowing,
+    stopFollowing,
+  };
+}

frontend/src/hooks/useLayerPanel.ts

@@ -0,0 +1,161 @@
+import { useCallback, useRef } from 'react';
+import type { PixiCanvasHandle } from '../canvas/PixiCanvas';
+import type { SelectionManager } from '../canvas/SelectionManager';
+import type { SceneItem } from '../canvas/SceneManager';
+import type { GroupObject } from '../canvas/scene-format';
+
+interface LayerItem {
+  id: string;
+  name: string;
+  type: string;
+  visible: boolean;
+  locked: boolean;
+  isGroup: boolean;
+  children?: LayerItem[];
+}
+
+interface LayerPanelDeps {
+  canvasRef: React.RefObject<PixiCanvasHandle | null>;
+  selectionRef: React.RefObject<SelectionManager | null>;
+  onCanvasChange: () => void;
+}
+
+function autoName(item: SceneItem, i: number, counters: Record<string, number>): string {
+  if (item.data.name) return item.data.name;
+  const type = item.data.type;
+  if (type === 'image') {
+    counters.image = (counters.image || 0) + 1;
+    return `Image ${counters.image}`;
+  }
+  if (type === 'text') {
+    const textData = item.data as any;
+    return (textData.text || 'Text').slice(0, 20);
+  }
+  if (type === 'group') {
+    const groupData = item.data as GroupObject;
+    return `Group (${groupData.children?.length || 0})`;
+  }
+  return `${type} ${i + 1}`;
+}
+
+function buildLayerItem(
+  item: SceneItem,
+  i: number,
+  counters: Record<string, number>,
+  getScene: () => ReturnType<PixiCanvasHandle['getScene']>,
+): LayerItem {
+  const isGroup = item.data.type === 'group';
+  let children: LayerItem[] | undefined;
+  if (isGroup) {
+    const groupData = item.data as GroupObject;
+    const scene = getScene();
+    if (scene && groupData.children) {
+      children = groupData.children.map((childId, ci) => {
+        const childItem = scene.getById(childId);
+        if (childItem) return buildLayerItem(childItem, ci, counters, getScene);
+        return { id: childId, name: `Missing ${childId.slice(0, 6)}`, type: 'unknown', visible: true, locked: false, isGroup: false };
+      });
+    }
+  }
+  return {
+    id: item.id,
+    name: autoName(item, i, counters),
+    type: item.data.type,
+    visible: item.data.visible,
+    locked: item.data.locked,
+    isGroup,
+    children,
+  };
+}
+
+/**
+ * Layer panel handlers — provides refresh function and all layer panel callbacks.
+ */
+export function useLayerPanel(deps: LayerPanelDeps) {
+  const { canvasRef, selectionRef, onCanvasChange } = deps;
+  const nameCounters = useRef<Record<string, number>>({});
+
+  const refreshLayers = useCallback((): LayerItem[] => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return [];
+    nameCounters.current = {};
+    const items = scene.getAllItems().sort((a, b) => a.data.z - b.data.z);
+    return items.map((item, i) =>
+      buildLayerItem(item, i, nameCounters.current, () => canvasRef.current?.getScene() ?? null),
+    );
+  }, [canvasRef]);
+
+  const onSelect = useCallback((id: string) => {
+    selectionRef.current?.selectOnly(id);
+  }, [selectionRef]);
+
+  const onToggleVisible = useCallback((id: string) => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return;
+    const item = scene.getById(id);
+    if (item) {
+      item.data.visible = !item.data.visible;
+      item.displayObject.visible = item.data.visible;
+      onCanvasChange();
+    }
+  }, [canvasRef, onCanvasChange]);
+
+  const onToggleLock = useCallback((id: string) => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return;
+    const item = scene.getById(id);
+    if (item) {
+      item.data.locked = !item.data.locked;
+      item.displayObject.eventMode = item.data.locked ? 'none' : 'static';
+    }
+  }, [canvasRef]);
+
+  const onReorder = useCallback((from: number, to: number) => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return;
+    const items = scene.getAllItems().sort((a, b) => a.data.z - b.data.z);
+    if (from < 0 || from >= items.length || to < 0 || to >= items.length) return;
+    const tmp = items[from].data.z;
+    items[from].data.z = items[to].data.z;
+    items[to].data.z = tmp;
+    scene._applyZOrder();
+    onCanvasChange();
+  }, [canvasRef, onCanvasChange]);
+
+  const onDelete = useCallback((id: string) => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return;
+    scene.removeItem(id, true);
+    selectionRef.current?.clear();
+    onCanvasChange();
+  }, [canvasRef, selectionRef, onCanvasChange]);
+
+  const onRename = useCallback((id: string, name: string) => {
+    const scene = canvasRef.current?.getScene();
+    if (!scene) return;
+    const item = scene.getById(id);
+    if (item) {
+      item.data.name = name;
+      // Also update frame label for groups
+      if (item.data.type === 'group') {
+        (item.data as any).label = name;
+        if (item.displayObject && 'setLabel' in item.displayObject) {
+          (item.displayObject as any).setLabel(name);
+        }
+      }
+      onCanvasChange(); // Broadcast rename to other clients
+    }
+  }, [canvasRef, onCanvasChange]);
+
+  return {
+    refreshLayers,
+    layerHandlers: {
+      onSelect,
+      onToggleVisible,
+      onToggleLock,
+      onReorder,
+      onDelete,
+      onRename,
+    },
+  };
+}

frontend/src/hooks/useSaveManager.ts

@@ -0,0 +1,66 @@
+import { useCallback, useRef } from 'react';
+import { saveCanvas } from '../api';
+import type { PixiCanvasHandle } from '../canvas/PixiCanvas';
+import type { SaveStatus } from '../components/StatusBar';
+
+interface SaveManagerOptions {
+  resolvedBoardId: string | undefined;
+  isPublicView?: boolean;
+  canvasRef: React.RefObject<PixiCanvasHandle | null>;
+  setSaveStatus: (s: SaveStatus) => void;
+}
+
+/**
+ * Debounced save with thumbnail generation from PixiJS renderer.
+ */
+export function useSaveManager({ resolvedBoardId, isPublicView, canvasRef, setSaveStatus }: SaveManagerOptions) {
+  const saveTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  const scheduleSave = useCallback(() => {
+    if (!resolvedBoardId || isPublicView) return;
+    setSaveStatus('unsaved');
+    if (saveTimerRef.current) clearTimeout(saveTimerRef.current);
+    saveTimerRef.current = setTimeout(async () => {
+      const scene = canvasRef.current?.getScene();
+      if (!scene) return;
+      setSaveStatus('saving');
+      try {
+        const state = JSON.stringify(scene.serialize());
+
+        // Generate thumbnail from PixiJS renderer
+        let thumbnail: string | undefined;
+        try {
+          const app = canvasRef.current?.getApp();
+          const viewport = canvasRef.current?.getViewport();
+          if (app?.renderer?.extract && viewport) {
+            const fullCanvas = app.renderer.extract.canvas(viewport) as HTMLCanvasElement;
+            const thumbMax = 400;
+            const sw = fullCanvas.width;
+            const sh = fullCanvas.height;
+            if (sw > 0 && sh > 0) {
+              const ratio = Math.min(thumbMax / sw, thumbMax / sh, 1);
+              const tw = Math.round(sw * ratio);
+              const th = Math.round(sh * ratio);
+              const offscreen = document.createElement('canvas');
+              offscreen.width = tw;
+              offscreen.height = th;
+              const ctx = offscreen.getContext('2d');
+              if (ctx) {
+                ctx.drawImage(fullCanvas, 0, 0, tw, th);
+                thumbnail = offscreen.toDataURL('image/webp', 0.6);
+              }
+            }
+          }
+        } catch (thumbErr) {
+          console.warn('Thumbnail generation failed:', thumbErr);
+        }
+        await saveCanvas(resolvedBoardId, state, thumbnail);
+        setSaveStatus('saved');
+      } catch {
+        setSaveStatus('unsaved');
+      }
+    }, 2000);
+  }, [resolvedBoardId, isPublicView, canvasRef, setSaveStatus]);
+
+  return { scheduleSave, saveTimerRef };
+}

frontend/src/hooks/useShortcutHandler.ts

@@ -0,0 +1,153 @@
+import { useEffect } from 'react';
+import type { PixiCanvasHandle } from '../canvas/PixiCanvas';
+import type { SelectionManager } from '../canvas/SelectionManager';
+import type { UndoManager } from '../canvas/history';
+import type { SceneItem } from '../canvas/SceneManager';
+import { getItemWorldBounds } from '../canvas/SceneManager';
+import { ToolType, toolShortcuts } from '../canvas/tools';
+import { ShortcutContext, matchesShortcut, sortBySpecificity } from '../canvas/shortcuts';
+import { shortcuts as shortcutDefs } from '../canvas/shortcut-definitions';
+import { writeCanvasToClipboard, pasteFromSystemClipboard } from '../canvas/clipboard';
+
+// Pre-sort shortcuts by specificity (most modifiers first) for correct matching
+const sortedShortcuts = sortBySpecificity(shortcutDefs);
+
+interface ShortcutHandlerDeps {
+  canvasRef: React.RefObject<PixiCanvasHandle | null>;
+  selectionRef: React.RefObject<SelectionManager | null>;
+  undoRef: React.RefObject<UndoManager | null>;
+  clipboardRef: React.MutableRefObject<SceneItem[]>;
+  resolvedBoardId: string | undefined;
+  onCanvasChange: () => void;
+  showToast: (msg: string) => void;
+  refreshLayers: () => void;
+  handleGroup: () => void;
+  handleUngroup: () => void;
+  setActiveTool: (t: ToolType) => void;
+  setCanUndo: (v: boolean) => void;
+  setCanRedo: (v: boolean) => void;
+  setZoom: (z: number) => void;
+  setShowGrid: React.Dispatch<React.SetStateAction<boolean>>;
+  setShowHelp: React.Dispatch<React.SetStateAction<boolean>>;
+  setFocusMode: React.Dispatch<React.SetStateAction<boolean>>;
+}
+
+/**
+ * Keyboard shortcut handler — registry-based, delegates to shortcut-definitions.
+ */
+export function useShortcutHandler(deps: ShortcutHandlerDeps) {
+  const {
+    canvasRef, selectionRef, undoRef, clipboardRef, resolvedBoardId,
+    onCanvasChange, showToast, refreshLayers,
+    handleGroup, handleUngroup,
+    setActiveTool, setCanUndo, setCanRedo, setZoom,
+    setShowGrid, setShowHelp, setFocusMode,
+  } = deps;
+
+  useEffect(() => {
+    async function onKeyDown(e: KeyboardEvent) {
+      if (e.target instanceof HTMLInputElement || e.target instanceof HTMLTextAreaElement) return;
+
+      const scene = canvasRef.current?.getScene();
+      const selection = selectionRef.current;
+      const viewport = canvasRef.current?.getViewport();
+      if (!scene || !selection || !viewport) return;
+
+      // Tool shortcuts (bare keys 1-5, v/h/p/t/e -- no modifiers)
+      if (!e.ctrlKey && !e.metaKey && !e.altKey) {
+        const tool = toolShortcuts[e.key.toLowerCase()];
+        if (tool) {
+          setActiveTool(tool);
+          return;
+        }
+      }
+
+      // Build context for shortcut handlers
+      const ctx: ShortcutContext = {
+        scene,
+        selection,
+        history: undoRef.current!,
+        viewport,
+        onChange: onCanvasChange,
+        clipboardRef,
+        writeCanvasToClipboard: async (items?: SceneItem[]) => {
+          try {
+            const app = canvasRef.current?.getApp() ?? null;
+            await writeCanvasToClipboard(app, viewport, items);
+          } catch (err: any) {
+            showToast('Copy failed: ' + (err.message || 'clipboard not available'));
+          }
+        },
+        showToast,
+        fitAll: () => canvasRef.current?.fitAll(),
+        setActiveTool,
+        setCanUndo,
+        setCanRedo,
+        refreshLayers,
+        handleGroup,
+        handleUngroup,
+        toggleGrid: () => setShowGrid((v) => !v),
+        toggleShowHelp: () => setShowHelp((v) => !v),
+        toggleFocusMode: () => setFocusMode((v) => !v),
+        pasteFromSystemClipboard: async (): Promise<string> => {
+          if (!resolvedBoardId) return 'No board';
+          const msg = await pasteFromSystemClipboard(scene, viewport, resolvedBoardId, onCanvasChange);
+          if (msg !== 'No image in clipboard') showToast(msg);
+          return msg;
+        },
+        fitSelection: () => {
+          const vp = canvasRef.current?.getViewport();
+          if (!vp || !selection) return;
+          const items = selection.getSelectedItems();
+          if (items.length === 0) return;
+          let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+          for (const item of items) {
+            const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
+            if (ix < minX) minX = ix;
+            if (iy < minY) minY = iy;
+            if (ix + iw > maxX) maxX = ix + iw;
+            if (iy + ih > maxY) maxY = iy + ih;
+          }
+          const padding = 60;
+          const contentW = maxX - minX + padding * 2;
+          const contentH = maxY - minY + padding * 2;
+          const scaleX = vp.screenWidth / contentW;
+          const scaleY = vp.screenHeight / contentH;
+          const targetScale = Math.min(scaleX, scaleY, 5);
+          vp.animate({
+            position: { x: (minX + maxX) / 2, y: (minY + maxY) / 2 },
+            scale: targetScale,
+            time: 300,
+            ease: 'easeOutQuad',
+          });
+        },
+      };
+
+      // Match against sorted registry (most-specific first)
+      for (const def of sortedShortcuts) {
+        if (!matchesShortcut(e, def)) continue;
+
+        // Check selection requirements
+        const activeCount = selection.selectedIds.size;
+        if (def.needsSelection && activeCount === 0) continue;
+        if (def.minSelection && activeCount < def.minSelection) continue;
+
+        e.preventDefault();
+        await def.handler(ctx);
+
+        // Update zoom display after any action
+        setZoom(canvasRef.current?.getZoom() ?? 1);
+        return;
+      }
+    }
+
+    window.addEventListener('keydown', onKeyDown);
+    return () => window.removeEventListener('keydown', onKeyDown);
+  }, [
+    canvasRef, selectionRef, undoRef, clipboardRef, resolvedBoardId,
+    onCanvasChange, showToast, refreshLayers,
+    handleGroup, handleUngroup,
+    setActiveTool, setCanUndo, setCanRedo, setZoom,
+    setShowGrid, setShowHelp, setFocusMode,
+  ]);
+}

frontend/src/pages/Editor.tsx

@@ -22,6 +22,7 @@ import SelectionToolbar from '../components/SelectionToolbar';
 import VideoControls from '../components/VideoControls';
 import ShortcutsHelp from '../components/ShortcutsHelp';
 import MattermostImport from '../components/MattermostImport';
+import Minimap from '../components/Minimap';
 import { InboxZone } from '../canvas/InboxZone';
 import { getItemWorldBounds } from '../canvas/SceneManager';
 import { VideoSprite } from '../canvas/sprites/VideoSprite';
@@ -33,6 +34,7 @@ import { useSaveManager } from '../hooks/useSaveManager';
 import { useCanvasSetup } from '../hooks/useCanvasSetup';
 import { useShortcutHandler } from '../hooks/useShortcutHandler';
 import { useLayerPanel } from '../hooks/useLayerPanel';
+import { useFollowMode } from '../hooks/useFollowMode';
 
 interface EditorProps {
   isPublicView?: boolean;
@@ -73,7 +75,7 @@ export default function Editor({ isPublicView }: EditorProps) {
   const [contextMenu, setContextMenu] = useState<{ x: number; y: number } | null>(null);
   const [toasts, setToasts] = useState<{ id: string; text: string }[]>([]);
   const [showLayers, setShowLayers] = useState(false);
-  const [showGrid, setShowGrid] = useState(false);
+  const [showGrid, setShowGrid] = useState(true);
   const [showHelp, setShowHelp] = useState(false);
   const [showMmImport, setShowMmImport] = useState(false);
   const [focusMode, setFocusMode] = useState(false);
@@ -81,6 +83,10 @@ export default function Editor({ isPublicView }: EditorProps) {
   const [selectedLayerIds, setSelectedLayerIds] = useState<string[]>([]);
   const [selToolbar, setSelToolbar] = useState<{ x: number; y: number; count: number } | null>(null);
   const [videoCtrl, setVideoCtrl] = useState<{ videoSprite: VideoSprite; screenRect: { x: number; y: number; w: number; h: number } } | null>(null);
+  const [showMinimap, setShowMinimap] = useState(true);
+  const [minimapData, setMinimapData] = useState<{ items: any[]; viewportBounds: any; contentBounds: any }>({
+    items: [], viewportBounds: { x: 0, y: 0, w: 1, h: 1 }, contentBounds: { x: 0, y: 0, w: 1, h: 1 },
+  });
 
   // Derived
   const { boardData, loading, error } = useBoardLoader(boardId);
@@ -112,6 +118,14 @@ export default function Editor({ isPublicView }: EditorProps) {
     if (vp) setCanvasTransform([vp.scale.x, 0, 0, vp.scale.y, vp.x, vp.y]);
   }, [scheduleSave]);
 
+  // Follow mode
+  const getViewport = useCallback(() => canvasRef.current?.getViewport() ?? null, []);
+  const { followingUserId, followingDisplayName, startFollowing, stopFollowing } = useFollowMode({
+    socket: getSocket(),
+    boardId: resolvedBoardId,
+    getViewport,
+  });
+
   // Canvas setup (selection, undo, sync, socket, drag/drop, paste, inbox)
   useCanvasSetup({
     boardData, resolvedBoardId, user, isPublicView,
@@ -156,11 +170,8 @@ export default function Editor({ isPublicView }: EditorProps) {
   }, [refreshLayerData]);
 
   useEffect(() => {
-    if (!showLayers) return;
+    if (showLayers) refreshLayers();
-    refreshLayers();
+  }, [showLayers, refreshLayers, selectedLayerIds]);
-    const interval = setInterval(refreshLayers, 500);
-    return () => clearInterval(interval);
-  }, [showLayers, refreshLayers]);
 
   // Grouping
   const handleGroup = useCallback(() => {
@@ -240,38 +251,36 @@ export default function Editor({ isPublicView }: EditorProps) {
     return () => window.removeEventListener('beforeunload', onBeforeUnload);
   }, [resolvedBoardId]);
 
-  // Zoom poll + selection toolbar position tracking
+  // Update UI overlays (selection toolbar, video controls, minimap) on demand
-  useEffect(() => {
+  const updateOverlays = useCallback(() => {
-    const interval = setInterval(() => {
+    const selection = selectionRef.current;
-      setZoom(canvasRef.current?.getZoom() ?? 1);
+    const vp = canvasRef.current?.getViewport();
+    if (!selection || !vp) { setSelToolbar(null); setVideoCtrl(null); return; }
+    const items = selection.getSelectedItems();
 
-      // Update selection toolbar position
+    setZoom(canvasRef.current?.getZoom() ?? 1);
-      const selection = selectionRef.current;
+    setCanvasTransform([vp.scale.x, 0, 0, vp.scale.y, vp.x, vp.y]);
-      const vp = canvasRef.current?.getViewport();
-      if (!selection || !vp) { setSelToolbar(null); setVideoCtrl(null); return; }
-      const items = selection.getSelectedItems();
 
-      // Video controls: show when exactly 1 video is selected
+    // Video controls: show when exactly 1 video is selected
-      if (items.length === 1 && items[0].type === 'video' && items[0].displayObject instanceof VideoSprite) {
+    if (items.length === 1 && items[0].type === 'video' && items[0].displayObject instanceof VideoSprite) {
-        const vs = items[0].displayObject as VideoSprite;
+      const vs = items[0].displayObject as VideoSprite;
-        const b = getItemWorldBounds(items[0]);
+      const b = getItemWorldBounds(items[0]);
-        const screenTL = vp.toScreen(b.x, b.y);
+      const screenTL = vp.toScreen(b.x, b.y);
-        const screenBR = vp.toScreen(b.x + b.w, b.y + b.h);
+      const screenBR = vp.toScreen(b.x + b.w, b.y + b.h);
-        setVideoCtrl({
+      setVideoCtrl({
-          videoSprite: vs,
+        videoSprite: vs,
-          screenRect: {
+        screenRect: {
-            x: screenTL.x,
+          x: screenTL.x,
-            y: screenTL.y,
+          y: screenTL.y,
-            w: screenBR.x - screenTL.x,
+          w: screenBR.x - screenTL.x,
-            h: screenBR.y - screenTL.y,
+          h: screenBR.y - screenTL.y,
-          },
+        },
-        });
+      });
-      } else {
+    } else {
-        setVideoCtrl(null);
+      setVideoCtrl(null);
-      }
+    }
-
-      if (items.length < 2) { setSelToolbar(null); return; }
 
+    if (items.length < 2) { setSelToolbar(null); } else {
       // Compute world bounding box of selection
       let minX = Infinity, minY = Infinity, maxX = -Infinity;
       for (const item of items) {
@@ -280,17 +289,65 @@ export default function Editor({ isPublicView }: EditorProps) {
         if (b.y < minY) minY = b.y;
         if (b.x + b.w > maxX) maxX = b.x + b.w;
       }
-
-      // Convert to screen
       const screenTL = vp.toScreen(minX, minY);
       const screenTR = vp.toScreen(maxX, minY);
-      const sx = (screenTL.x + screenTR.x) / 2;
+      setSelToolbar({ x: (screenTL.x + screenTR.x) / 2, y: screenTL.y, count: items.length });
-      const sy = screenTL.y;
+    }
-      setSelToolbar({ x: sx, y: sy, count: items.length });
+
-    }, 100);
+    // Minimap data
-    return () => clearInterval(interval);
+    const scene = canvasRef.current?.getScene();
+    if (scene) {
+      const allItems = scene.getTopLevelItems();
+      const mapItems = allItems.map((it) => {
+        const b = getItemWorldBounds(it);
+        return { x: b.x, y: b.y, w: b.w, h: b.h, type: it.type, id: it.id };
+      });
+      const topLeft = vp.toWorld(0, 0);
+      const botRight = vp.toWorld(vp.screenWidth, vp.screenHeight);
+      const vpBounds = { x: topLeft.x, y: topLeft.y, w: botRight.x - topLeft.x, h: botRight.y - topLeft.y };
+      let cMinX = Infinity, cMinY = Infinity, cMaxX = -Infinity, cMaxY = -Infinity;
+      for (const it of mapItems) {
+        if (it.x < cMinX) cMinX = it.x;
+        if (it.y < cMinY) cMinY = it.y;
+        if (it.x + it.w > cMaxX) cMaxX = it.x + it.w;
+        if (it.y + it.h > cMaxY) cMaxY = it.y + it.h;
+      }
+      if (mapItems.length === 0) { cMinX = 0; cMinY = 0; cMaxX = 1; cMaxY = 1; }
+      setMinimapData({
+        items: mapItems,
+        viewportBounds: vpBounds,
+        contentBounds: { x: cMinX, y: cMinY, w: cMaxX - cMinX, h: cMaxY - cMinY },
+      });
+    }
   }, []);
 
+  // Listen to viewport moved event for overlay updates (throttled)
+  // Depends on objectCount so it re-runs after canvas init (viewport becomes available)
+  useEffect(() => {
+    const vp = canvasRef.current?.getViewport();
+    if (!vp) return;
+    let rafId: number | null = null;
+    const onMoved = () => {
+      if (rafId) return;
+      rafId = requestAnimationFrame(() => { rafId = null; updateOverlays(); });
+    };
+    vp.on('moved', onMoved);
+    // Also listen to wheel events directly for immediate zoom feedback
+    const onWheel = () => {
+      if (rafId) return;
+      rafId = requestAnimationFrame(() => { rafId = null; updateOverlays(); });
+    };
+    vp.on('wheel-scroll', onWheel);
+    return () => { vp.off('moved', onMoved); vp.off('wheel-scroll', onWheel); if (rafId) cancelAnimationFrame(rafId); };
+  }, [updateOverlays, objectCount]);
+
+  // Also update overlays when selection or scene changes
+  useEffect(() => {
+    updateOverlays();
+  }, [selectedLayerIds, updateOverlays]);
+
+  // (PresenceOverlay removed — selection broadcast no longer needed)
+
   // -- Render --
 
   if (loading) {
@@ -399,6 +456,8 @@ export default function Editor({ isPublicView }: EditorProps) {
           setZoom(z);
         }}
         onlineUsers={onlineUsers}
+        onUserClick={startFollowing}
+        followingUserId={followingUserId}
         onToggleLayers={() => setShowLayers((v) => !v)}
         showLayers={showLayers}
         onToggleHelp={() => setShowHelp((v) => !v)}
@@ -421,23 +480,32 @@ export default function Editor({ isPublicView }: EditorProps) {
           canvasTransform={canvasTransform}
         />
 
-        {/* Grid overlay */}
+        {/* Dot grid overlay — adapts spacing at zoom levels like Figma */}
-        {showGrid && (
+        {showGrid && (() => {
-          <svg
+          const scale = canvasTransform[0] || 1;
-            style={{ position: 'absolute', inset: 0, pointerEvents: 'none', zIndex: 1 }}
+          const tx = canvasTransform[4] || 0;
-            width="100%" height="100%"
+          const ty = canvasTransform[5] || 0;
-          >
+          // Adaptive spacing: base 20px, doubles when dots get too dense, halves when too sparse
-            <defs>
+          let spacing = 20;
-              <pattern id="grid50" width={50 * (canvasTransform[0] || 1)} height={50 * (canvasTransform[3] || 1)} patternUnits="userSpaceOnUse"
+          while (spacing * scale < 12) spacing *= 2;
-                x={(canvasTransform[4] || 0) % (50 * (canvasTransform[0] || 1))}
+          while (spacing * scale > 50) spacing /= 2;
-                y={(canvasTransform[5] || 0) % (50 * (canvasTransform[3] || 1))}>
+          const screenSpacing = spacing * scale;
-                <line x1="0" y1="0" x2={50 * (canvasTransform[0] || 1)} y2="0" stroke="rgba(255,255,255,0.04)" strokeWidth="1" />
+          const dotR = Math.max(0.5, Math.min(1.2, scale * 0.6));
-                <line x1="0" y1="0" x2="0" y2={50 * (canvasTransform[3] || 1)} stroke="rgba(255,255,255,0.04)" strokeWidth="1" />
+          const ox = tx % screenSpacing;
-              </pattern>
+          const oy = ty % screenSpacing;
-            </defs>
+          // Subtle dot: brighter at high zoom, dimmer at low zoom
-            <rect width="100%" height="100%" fill="url(#grid50)" />
+          const alpha = Math.max(0.08, Math.min(0.25, scale * 0.12));
-          </svg>
+          return (
-        )}
+            <svg style={{ position: 'absolute', inset: 0, pointerEvents: 'none', zIndex: 1 }} width="100%" height="100%">
+              <defs>
+                <pattern id="dotgrid" width={screenSpacing} height={screenSpacing} patternUnits="userSpaceOnUse" x={ox} y={oy}>
+                  <circle cx={dotR} cy={dotR} r={dotR} fill={`rgba(255,255,255,${alpha})`} />
+                </pattern>
+              </defs>
+              <rect width="100%" height="100%" fill="url(#dotgrid)" />
+            </svg>
+          );
+        })()}
 
         {/* Empty canvas guide */}
         {objectCount === 0 && (
@@ -459,23 +527,23 @@ export default function Editor({ isPublicView }: EditorProps) {
             x={selToolbar.x}
             y={selToolbar.y}
             count={selToolbar.count}
-            onAlignLeft={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignLeft(s); onCanvasChange(); } }}
+            onAlignLeft={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignLeft(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onAlignCenterH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignCenterH(s); onCanvasChange(); } }}
+            onAlignCenterH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignCenterH(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onAlignRight={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignRight(s); onCanvasChange(); } }}
+            onAlignRight={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignRight(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onAlignTop={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignTop(s); onCanvasChange(); } }}
+            onAlignTop={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignTop(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onAlignCenterV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignCenterV(s); onCanvasChange(); } }}
+            onAlignCenterV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignCenterV(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onAlignBottom={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignBottom(s); onCanvasChange(); } }}
+            onAlignBottom={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.alignBottom(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onDistributeH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.distributeHorizontal(s); onCanvasChange(); } }}
+            onDistributeH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.distributeHorizontal(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onDistributeV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.distributeVertical(s); onCanvasChange(); } }}
+            onDistributeV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.distributeVertical(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onPack={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeOptimal(s); onCanvasChange(); } }}
+            onPack={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeOptimal(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onGrid={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeGrid(s); onCanvasChange(); } }}
+            onGrid={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeGrid(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onRow={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeRow(s); onCanvasChange(); } }}
+            onRow={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeRow(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onColumn={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeColumn(s); onCanvasChange(); } }}
+            onColumn={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.arrangeColumn(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onStack={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.stackObjects(s); onCanvasChange(); } }}
+            onStack={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.stackObjects(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onFlipH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.flipHorizontal(s); onCanvasChange(); } }}
+            onFlipH={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.flipHorizontal(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
-            onFlipV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.flipVertical(s); onCanvasChange(); } }}
+            onFlipV={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.flipVertical(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
             onGroup={handleGroup}
-            onNormSize={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.normalizeSize(s); onCanvasChange(); } }}
+            onNormSize={() => { const s = selectionRef.current?.getSelectedItems(); if (s) { ops.normalizeSize(s); selectionRef.current?.transformBox.update(s); onCanvasChange(); } }}
           />
         )}
 
@@ -487,6 +555,31 @@ export default function Editor({ isPublicView }: EditorProps) {
           />
         )}
 
+        {/* Minimap */}
+        {showMinimap && !focusMode && objectCount > 0 && (
+          <Minimap
+            items={minimapData.items}
+            viewportBounds={minimapData.viewportBounds}
+            contentBounds={minimapData.contentBounds}
+            onNavigate={(wx, wy) => {
+              const vp = canvasRef.current?.getViewport();
+              if (vp) vp.animate({ time: 200, position: { x: wx, y: wy }, ease: 'easeOutQuad' });
+            }}
+          />
+        )}
+
+        {/* Follow mode banner */}
+        {followingDisplayName && (
+          <div style={{
+            position: 'absolute', top: '8px', left: '50%', transform: 'translateX(-50%)',
+            padding: '4px 14px', background: 'rgba(74, 144, 217, 0.9)', borderRadius: '8px',
+            color: '#fff', fontSize: '12px', fontWeight: 500, zIndex: 200,
+            cursor: 'pointer', pointerEvents: 'auto',
+          }} onClick={stopFollowing}>
+            Following {followingDisplayName} — click to stop
+          </div>
+        )}
+
         {/* Context menu */}
         {contextMenu && (
           <ContextMenu