diff --git a/frontend/src/canvas/SelectionManager.ts b/frontend/src/canvas/SelectionManager.ts
index b0fb141..5e78a39 100644
--- a/frontend/src/canvas/SelectionManager.ts
+++ b/frontend/src/canvas/SelectionManager.ts
@@ -7,10 +7,10 @@
 
 import { Container, Graphics, FederatedPointerEvent } from 'pixi.js';
 import type { Viewport } from 'pixi-viewport';
-import { SceneManager, SceneItem } from './SceneManager';
+import { SceneManager, SceneItem, getItemWorldBounds, isGroupChild } from './SceneManager';
 import { TransformBox } from './TransformBox';
 import { ImageSprite } from './sprites/ImageSprite';
-import { Spring, PRESETS } from './spring';
+import { VideoSprite } from './sprites/VideoSprite';
 
 // ---------------------------------------------------------------------------
 // Constants
@@ -23,7 +23,6 @@ const BAND_STROKE_ALPHA = 0.6;
 const BAND_STROKE_WIDTH = 1;
 const RUBBER_BAND_THRESHOLD = 5; // px in screen space before rubber band activates
 const DRAG_THRESHOLD = 5;        // px in screen space before object drag activates
-const DRAG_LIFT_SCALE = 1.03;    // scale during drag
 
 // ---------------------------------------------------------------------------
 // SelectionManager
@@ -38,6 +37,7 @@ export class SelectionManager {
   private _overlay: Container;
   private _bandGfx: Graphics;
   private _onSelectionChange: ((ids: string[]) => void) | null = null;
+  private _onItemTransform: ((item: SceneItem) => void) | null = null;
 
   // Pointer state
   private _pointerDown = false;
@@ -53,6 +53,15 @@ export class SelectionManager {
   private _lastDragWorldX = 0;
   private _lastDragWorldY = 0;
 
+  // Double-click detection
+  private _lastClickTime = 0;
+  private _lastClickItemId: string | null = null;
+  private static readonly DOUBLE_CLICK_MS = 400;
+
+  private _onDoubleClickText: ((item: SceneItem) => void) | null = null;
+
+  private _enabled = true;
+
   constructor(viewport: Viewport, scene: SceneManager) {
     this._viewport = viewport;
     this._scene = scene;
@@ -79,12 +88,32 @@ export class SelectionManager {
     viewport.on('pointerupoutside', this._onPointerUp, this);
   }
 
+  /** Enable/disable selection interaction (disable during draw/text/eraser tools). */
+  setEnabled(enabled: boolean): void {
+    this._enabled = enabled;
+    if (!enabled) {
+      this._pointerDown = false;
+      this._rubberBanding = false;
+      this._bandGfx.visible = false;
+    }
+  }
+
   // -- Public API -----------------------------------------------------------
 
   set onSelectionChange(fn: (ids: string[]) => void) {
     this._onSelectionChange = fn;
   }
 
+  /** Called during drag with each moved item for live sync broadcast. */
+  set onItemTransform(fn: (item: SceneItem) => void) {
+    this._onItemTransform = fn;
+  }
+
+  /** Called on double-click of a text item (for inline editing). */
+  set onDoubleClickText(fn: (item: SceneItem) => void) {
+    this._onDoubleClickText = fn;
+  }
+
   /** Select only this item, deselecting everything else. */
   selectOnly(id: string): void {
     this.selectedIds.clear();
@@ -105,7 +134,7 @@ export class SelectionManager {
   /** Select all unlocked, visible items. */
   selectAll(): void {
     this.selectedIds.clear();
-    for (const item of this._scene.getAllItems()) {
+    for (const item of this._scene.getTopLevelItems()) {
       if (!item.data.locked && item.data.visible) {
         this.selectedIds.add(item.id);
       }
@@ -134,7 +163,7 @@ export class SelectionManager {
 
   /** Check all scene items in reverse z-order; return first whose world bounds contain (wx, wy). */
   _hitTest(wx: number, wy: number): SceneItem | null {
-    const all = this._scene.getAllItems();
+    const all = this._scene.getTopLevelItems();
     // Sort by z descending (topmost first)
     all.sort((a, b) => b.data.z - a.data.z);
 
@@ -142,11 +171,7 @@ export class SelectionManager {
       if (item.data.locked) continue;
       if (!item.data.visible) continue;
 
-      // Use item.data (world-space) instead of getBounds() (screen-space)
-      const ix = item.data.x;
-      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);
+      const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
 
       if (ix <= wx && wx <= ix + iw && iy <= wy && wy <= iy + ih) {
         return item;
@@ -158,6 +183,7 @@ export class SelectionManager {
   // -- Pointer Handlers -----------------------------------------------------
 
   private _onPointerDown(e: FederatedPointerEvent): void {
+    if (!this._enabled) return;
     // Only handle primary button
     if (e.button !== 0) return;
 
@@ -212,14 +238,16 @@ export class SelectionManager {
         this._lastDragWorldX = currentWorld.x;
         this._lastDragWorldY = currentWorld.y;
 
-        // Move all selected items by delta
-        for (const item of this.getSelectedItems()) {
+        // Move all selected items by delta and broadcast transforms
+        const selected = this.getSelectedItems();
+        for (const item of selected) {
           item.displayObject.x += ddx;
           item.displayObject.y += ddy;
           item.data.x = item.displayObject.x;
           item.data.y = item.displayObject.y;
+          this._onItemTransform?.(item);
         }
-        this.transformBox.update(this.getSelectedItems());
+        this.transformBox.update(selected);
       }
       return;
     }
@@ -268,6 +296,26 @@ export class SelectionManager {
       if (!e.shiftKey) {
         this.clear();
       }
+    } else if (this._hitItemOnDown && !this._objectDragging) {
+      // Click (no drag) on an item — check for double-click
+      const now = Date.now();
+      const item = this._hitItemOnDown;
+      if (
+        this._lastClickItemId === item.id &&
+        now - this._lastClickTime < SelectionManager.DOUBLE_CLICK_MS
+      ) {
+        // Double-click detected
+        if (item.displayObject instanceof VideoSprite) {
+          item.displayObject.togglePlayPause();
+        } else if (item.type === 'text') {
+          this._onDoubleClickText?.(item);
+        }
+        this._lastClickTime = 0;
+        this._lastClickItemId = null;
+      } else {
+        this._lastClickTime = now;
+        this._lastClickItemId = item.id;
+      }
     }
 
     this._hitItemOnDown = null;
@@ -275,43 +323,23 @@ export class SelectionManager {
 
   // -- Drag Shadow Lift / Drop ----------------------------------------------
 
-  /** Lift shadows and spring-scale selected items up for drag. */
+  /** Lift shadows on selected items for drag. */
   private _applyLift(): void {
-    const items = this.getSelectedItems();
-    for (const item of items) {
-      const dobj = item.displayObject;
-
-      // Lift shadow on ImageSprites
-      if (dobj instanceof ImageSprite) {
-        dobj.liftShadow();
+    for (const item of this.getSelectedItems()) {
+      const obj = item.displayObject;
+      if (obj instanceof ImageSprite || obj instanceof VideoSprite) {
+        obj.liftShadow();
       }
-
-      // Spring scale 1.0 → 1.03
-      const spring = new Spring(1.0, DRAG_LIFT_SCALE, PRESETS.snappy);
-      spring.onUpdate = (v) => {
-        dobj.scale.set(v, v);
-      };
-      this._scene.springs.add(spring);
     }
   }
 
-  /** Drop shadows and spring-scale selected items back to rest. */
+  /** Drop shadows on selected items after drag. */
   private _applyDrop(): void {
-    const items = this.getSelectedItems();
-    for (const item of items) {
-      const dobj = item.displayObject;
-
-      // Drop shadow on ImageSprites
-      if (dobj instanceof ImageSprite) {
-        dobj.dropShadow();
+    for (const item of this.getSelectedItems()) {
+      const obj = item.displayObject;
+      if (obj instanceof ImageSprite || obj instanceof VideoSprite) {
+        obj.dropShadow();
       }
-
-      // Spring scale 1.03 → 1.0
-      const spring = new Spring(DRAG_LIFT_SCALE, 1.0, PRESETS.snappy);
-      spring.onUpdate = (v) => {
-        dobj.scale.set(v, v);
-      };
-      this._scene.springs.add(spring);
     }
   }
 
@@ -342,14 +370,10 @@ export class SelectionManager {
       this.selectedIds.clear();
     }
 
-    for (const item of this._scene.getAllItems()) {
+    for (const item of this._scene.getTopLevelItems()) {
       if (item.data.locked || !item.data.visible) continue;
 
-      // Use world-space data instead of screen-space getBounds()
-      const ix = item.data.x;
-      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);
+      const { x: ix, y: iy, w: iw, h: ih } = getItemWorldBounds(item);
 
       // Check intersection between rubber band rect and item world bounds
       const intersects =
diff --git a/frontend/src/canvas/TextEditor.ts b/frontend/src/canvas/TextEditor.ts
new file mode 100644
index 0000000..4fa9f5a
--- /dev/null
+++ b/frontend/src/canvas/TextEditor.ts
@@ -0,0 +1,182 @@
+/**
+ * TextEditor — inline text editing overlay for PixiJS Text objects.
+ *
+ * Shows an absolutely-positioned <textarea> over the text item,
+ * matching its font, size (scaled by zoom), and color.
+ * Commits on blur/Enter, cancels on Escape.
+ */
+
+import { Text } from 'pixi.js';
+import type { Viewport } from 'pixi-viewport';
+import type { SceneItem } from './SceneManager';
+import type { TextObject } from './scene-format';
+
+export class TextEditor {
+  private _textarea: HTMLTextAreaElement | null = null;
+  private _item: SceneItem | null = null;
+  private _viewport: Viewport | null = null;
+  private _container: HTMLElement | null = null;
+  private _onChange: (() => void) | null = null;
+  private _originalText: string = '';
+
+  /** True when a textarea is open. */
+  get isEditing(): boolean {
+    return this._textarea !== null;
+  }
+
+  /**
+   * Open an inline textarea over the given text item.
+   */
+  startEditing(
+    item: SceneItem,
+    viewport: Viewport,
+    container: HTMLElement,
+    onChange: () => void,
+  ): void {
+    // Only text items
+    if (item.type !== 'text') return;
+    const pixiText = item.displayObject;
+    if (!(pixiText instanceof Text)) return;
+
+    // Prevent double-open
+    if (this._textarea) this.stopEditing(false);
+
+    this._item = item;
+    this._viewport = viewport;
+    this._container = container;
+    this._onChange = onChange;
+
+    const data = item.data as TextObject;
+    this._originalText = data.text;
+
+    // Hide the PixiJS text while editing
+    pixiText.visible = false;
+
+    // Compute screen position of the text
+    const worldPos = pixiText.getGlobalPosition();
+    const renderer = viewport.parent?.parent; // stage -> app (not reliable)
+    // Use viewport.toScreen to convert world → screen coords
+    const screen = viewport.toScreen(item.data.x, item.data.y);
+    const zoom = viewport.scale.x;
+
+    // Scaled font size
+    const scaledFontSize = data.fontSize * zoom * Math.abs(item.data.sx);
+
+    // Create textarea
+    const ta = document.createElement('textarea');
+    ta.value = data.text;
+    ta.style.position = 'absolute';
+    ta.style.left = `${screen.x}px`;
+    ta.style.top = `${screen.y}px`;
+    ta.style.fontSize = `${scaledFontSize}px`;
+    ta.style.fontFamily = data.fontFamily;
+    ta.style.color = data.fill;
+    ta.style.background = 'transparent';
+    ta.style.border = 'none';
+    ta.style.outline = 'none';
+    ta.style.resize = 'none';
+    ta.style.overflow = 'hidden';
+    ta.style.padding = '0';
+    ta.style.margin = '0';
+    ta.style.lineHeight = '1.2';
+    ta.style.whiteSpace = 'pre';
+    ta.style.zIndex = '1000';
+    ta.style.minWidth = '20px';
+    ta.style.minHeight = `${scaledFontSize * 1.3}px`;
+    ta.style.transformOrigin = 'top left';
+    // Apply rotation if any
+    if (item.data.angle) {
+      ta.style.transform = `rotate(${item.data.angle}deg)`;
+    }
+
+    // Auto-size the textarea to fit content
+    const autoSize = () => {
+      ta.style.height = 'auto';
+      ta.style.width = 'auto';
+      // Use a hidden measurement trick: set to scroll dimensions
+      ta.style.height = `${ta.scrollHeight}px`;
+      ta.style.width = `${Math.max(ta.scrollWidth + 4, 20)}px`;
+    };
+
+    // Event handlers
+    const onKeyDown = (e: KeyboardEvent) => {
+      e.stopPropagation(); // Prevent canvas shortcuts
+      if (e.key === 'Escape') {
+        e.preventDefault();
+        this.stopEditing(false);
+      } else if (e.key === 'Enter' && !e.shiftKey) {
+        e.preventDefault();
+        this.stopEditing(true);
+      }
+    };
+
+    const onBlur = () => {
+      // Small delay to allow Escape to fire first
+      setTimeout(() => {
+        if (this._textarea === ta) {
+          this.stopEditing(true);
+        }
+      }, 0);
+    };
+
+    const onInput = () => {
+      autoSize();
+    };
+
+    ta.addEventListener('keydown', onKeyDown);
+    ta.addEventListener('blur', onBlur);
+    ta.addEventListener('input', onInput);
+
+    container.appendChild(ta);
+    this._textarea = ta;
+
+    // Initial size and focus
+    autoSize();
+    ta.focus();
+    ta.select();
+  }
+
+  /**
+   * Close the textarea. If save=true, commit the text; otherwise restore original.
+   */
+  stopEditing(save: boolean): void {
+    const ta = this._textarea;
+    const item = this._item;
+    if (!ta || !item) return;
+
+    const pixiText = item.displayObject;
+    if (!(pixiText instanceof Text)) return;
+
+    const data = item.data as TextObject;
+
+    if (save) {
+      const newText = ta.value || this._originalText; // Don't allow empty
+      data.text = newText;
+      pixiText.text = newText;
+
+      // Update dimensions from measured PixiJS text bounds
+      pixiText.visible = true;
+      const bounds = pixiText.getLocalBounds();
+      data.w = bounds.width;
+      data.h = bounds.height;
+
+      this._onChange?.();
+    } else {
+      // Restore original text
+      data.text = this._originalText;
+      pixiText.text = this._originalText;
+      pixiText.visible = true;
+    }
+
+    // Remove textarea from DOM
+    ta.remove();
+
+    // Reset state
+    this._textarea = null;
+    this._item = null;
+    this._viewport = null;
+    this._container = null;
+    this._onChange = null;
+    this._originalText = '';
+  }
+}
diff --git a/frontend/src/hooks/useCanvasSetup.ts b/frontend/src/hooks/useCanvasSetup.ts
new file mode 100644
index 0000000..08aab90
--- /dev/null
+++ b/frontend/src/hooks/useCanvasSetup.ts
@@ -0,0 +1,216 @@
+import { useEffect, useRef } from 'react';
+import type { PixiCanvasHandle } from '../canvas/PixiCanvas';
+import { SelectionManager } from '../canvas/SelectionManager';
+import { TextEditor } from '../canvas/TextEditor';
+import { setupSync, SyncHandle } from '../canvas/sync';
+import { setupDragDrop, setupPaste } from '../canvas/image-drop';
+import { UndoManager } from '../canvas/history';
+import { InboxZone } from '../canvas/InboxZone';
+import { connectSocket, disconnectSocket } from '../socket';
+
+interface OnlineUser {
+  userId: string;
+  displayName: string;
+  color: string;
+}
+
+const CURSOR_COLORS = [
+  '#ff6b6b', '#ffa94d', '#ffd43b', '#69db7c', '#38d9a9',
+  '#4dabf7', '#7950f2', '#e64980', '#20c997', '#ff922b',
+];
+
+function userColor(userId: string): string {
+  let hash = 0;
+  for (let i = 0; i < userId.length; i++) {
+    hash = ((hash << 5) - hash) + userId.charCodeAt(i);
+    hash |= 0;
+  }
+  return CURSOR_COLORS[Math.abs(hash) % CURSOR_COLORS.length];
+}
+
+interface CanvasSetupDeps {
+  boardData: any;
+  resolvedBoardId: string | undefined;
+  user: any;
+  isPublicView?: boolean;
+  canvasRef: React.RefObject<PixiCanvasHandle | null>;
+  selectionRef: React.MutableRefObject<SelectionManager | null>;
+  undoRef: React.MutableRefObject<UndoManager | null>;
+  syncRef: React.MutableRefObject<SyncHandle | null>;
+  inboxZoneRef: React.MutableRefObject<InboxZone | null>;
+  onCanvasChange: () => void;
+  showToast: (msg: string) => void;
+  setOnlineUsers: React.Dispatch<React.SetStateAction<OnlineUser[]>>;
+  setSelectedLayerIds: React.Dispatch<React.SetStateAction<string[]>>;
+}
+
+/**
+ * Sets up the canvas infrastructure: selection, undo, sync, socket, drag/drop, paste, inbox zone.
+ * Runs once when boardData is loaded and canvas is ready.
+ */
+export function useCanvasSetup(deps: CanvasSetupDeps) {
+  const {
+    boardData, resolvedBoardId, user, isPublicView,
+    canvasRef, selectionRef, undoRef, syncRef, inboxZoneRef,
+    onCanvasChange, showToast, setOnlineUsers, setSelectedLayerIds,
+  } = deps;
+
+  const dropCleanupRef = useRef<(() => void) | null>(null);
+  const pasteCleanupRef = useRef<(() => void) | null>(null);
+
+  useEffect(() => {
+    if (!boardData || !resolvedBoardId) return;
+
+    const timer = setTimeout(() => {
+      const scene = canvasRef.current?.getScene();
+      const viewport = canvasRef.current?.getViewport();
+      if (!scene || !viewport) return;
+
+      // Create SelectionManager
+      const selection = new SelectionManager(viewport, scene);
+      selectionRef.current = selection;
+
+      // Wire selection change to update layer panel state
+      selection.onSelectionChange = (ids: string[]) => {
+        setSelectedLayerIds(ids);
+      };
+
+      // Inline text editing on double-click
+      const textEditor = new TextEditor();
+      // Find the DOM container for the canvas (parent of the <canvas> element)
+      const canvasElements = document.querySelectorAll('canvas');
+      let domContainer: HTMLElement | null = null;
+      for (const c of canvasElements) {
+        if (c.parentElement && c.width > 100) {
+          domContainer = c.parentElement;
+          break;
+        }
+      }
+      selection.onDoubleClickText = (item) => {
+        if (!domContainer) return;
+        textEditor.startEditing(item, viewport, domContainer, () => {
+          syncRef.current?.broadcastElements([item.id]);
+          onCanvasChange();
+        });
+      };
+
+      // Refresh transform box when item dimensions change (e.g. video metadata loaded)
+      scene.onItemDimensionsChanged = (itemId: string) => {
+        if (selection.selectedIds.has(itemId)) {
+          selection.transformBox.update(selection.getSelectedItems());
+        }
+      };
+
+      // Create UndoManager
+      undoRef.current = new UndoManager(scene);
+
+      // Create InboxZone and add to viewport
+      const inboxZone = new InboxZone(scene.textures, scene.springs);
+      viewport.addChild(inboxZone);
+      inboxZoneRef.current = inboxZone;
+
+      if (user) {
+        const socket = connectSocket();
+
+        syncRef.current = setupSync(scene, socket, resolvedBoardId, {
+          onRemoteTransform: (item) => {
+            if (selection.selectedIds.has(item.id)) {
+              selection.transformBox.update(selection.getSelectedItems());
+            }
+          },
+        });
+
+        // Wire live drag/resize transforms to sync broadcast
+        selection.onItemTransform = (item) => {
+          syncRef.current?.broadcastTransform(item);
+        };
+        selection.transformBox.onItemTransform = (item) => {
+          syncRef.current?.broadcastTransform(item);
+        };
+
+        socket.on('user:joined', (data: any) => {
+          const uid = data.userId || data.id;
+          const name = data.displayName || data.display_name || data.username || '';
+          setOnlineUsers((prev) => {
+            if (prev.find((u) => u.userId === uid)) return prev;
+            return [...prev, { userId: uid, displayName: name, color: userColor(uid) }];
+          });
+          if (name) showToast(`${name} joined`);
+        });
+
+        socket.on('user:left', (data: any) => {
+          const uid = data.userId || data.id;
+          const name = data.displayName || data.display_name || data.username || '';
+          setOnlineUsers((prev) => prev.filter((u) => u.userId !== uid));
+          if (name) showToast(`${name} left`);
+        });
+
+        socket.on('room:users', (data: any) => {
+          if (Array.isArray(data.users)) {
+            setOnlineUsers(data.users.map((u: any) => ({
+              userId: u.userId || u.id,
+              displayName: u.displayName || u.display_name || u.username || '',
+              color: userColor(u.userId || u.id),
+            })));
+          }
+        });
+
+        socket.on('board:media-arrived', (data: any) => {
+          const assets = data?.assets;
+          if (Array.isArray(assets) && assets.length > 0 && inboxZoneRef.current) {
+            inboxZoneRef.current.addMedia(assets);
+            showToast(`${assets.length} image${assets.length !== 1 ? 's' : ''} arrived in Inbox`);
+          }
+        });
+
+        // Cursor tracking — throttled to ~30fps to avoid flooding the socket
+        let cursorTimer: ReturnType<typeof setTimeout> | null = null;
+        const onPointerMove = (e: any) => {
+          if (cursorTimer) return;
+          const world = viewport.toWorld(e.global.x, e.global.y);
+          socket.emit('cursor:move', {
+            boardId: resolvedBoardId,
+            x: world.x,
+            y: world.y,
+          });
+          cursorTimer = setTimeout(() => { cursorTimer = null; }, 33);
+        };
+        viewport.on('pointermove', onPointerMove);
+      }
+
+      // Setup drag/drop and paste
+      if (!isPublicView || user) {
+        const canvasElements = document.querySelectorAll('canvas');
+        let domContainer: HTMLElement | null = null;
+        for (const c of canvasElements) {
+          if (c.parentElement && c.width > 100) {
+            domContainer = c.parentElement;
+            break;
+          }
+        }
+
+        if (domContainer) {
+          dropCleanupRef.current = setupDragDrop(domContainer, viewport, scene, resolvedBoardId, onCanvasChange);
+          pasteCleanupRef.current = setupPaste(viewport, scene, resolvedBoardId, onCanvasChange);
+        } else {
+          pasteCleanupRef.current = setupPaste(viewport, scene, resolvedBoardId, onCanvasChange);
+        }
+      }
+    }, 200);
+
+    return () => {
+      clearTimeout(timer);
+      selectionRef.current?.destroy();
+      selectionRef.current = null;
+      if (inboxZoneRef.current) {
+        inboxZoneRef.current.clear();
+        inboxZoneRef.current.destroy({ children: true });
+        inboxZoneRef.current = null;
+      }
+      syncRef.current?.cleanup();
+      dropCleanupRef.current?.();
+      pasteCleanupRef.current?.();
+      disconnectSocket();
+    };
+  }, [boardData, resolvedBoardId, user, isPublicView, onCanvasChange, showToast, canvasRef, selectionRef, undoRef, syncRef, inboxZoneRef, setOnlineUsers, setSelectedLayerIds]);
+}