The media bin's grid always requested the FULL original file for a
thumbnail (an <img>/video-frame decode of the whole thing, only
cropped down visually via CSS/canvas afterward). A 4K photo or a
multi-MB clip got fully downloaded and decoded just to show a 96px
square, every render.
Added GET /api/media/{mid}/thumb: generates a small JPEG on first
request (Pillow resize for images, one ffmpeg frame-grab for video),
caches it under media/thumbnails/, and serves that instead. Deleting
a media item removes its cached thumbnail too. mediabrowser.js now
loads from this endpoint for both image and video kinds -- the same
canvas-drawing path as before, just fed a file that's already small
instead of the original. Measured live: a 1.57MB test clip's cached
thumbnail is 1.6KB.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
