- Upload route now generates 3-tier LOD (thumb/medium/full) for images via
lod-generator service, storing each tier at boards/{boardId}/{imageId}/
- Video uploads (mp4, webm, quicktime) supported as single-file storage
- New DB columns: asset_key (prefix path) and media_type ('image'/'video')
- Backward compatible: minio_path and public_url still populated (point to full tier)
- SVG and GIF skip LOD processing (single file stored)
- Added putBuffer() and MIME_TO_EXT export to minio.js