Cards showed "Failed to load" for thumbnails that were valid on disk. The
browser had fetched them while the thumbnail run was still writing the
file and, because image responses are cached for an hour, kept the broken
bytes. The card also had no fallback to the original.
- image and video thumbnails are written to a hidden temp sibling and
renamed into place, so a partial file is never visible at the final path
- every thumbnail_url (gallery listing, prompt images, duplicates, autotag
listing) carries ?v=<mtime>, so a regenerated thumbnail gets a new URL
instead of the cached old one
- a 404 from the image serve route is marked no-store; ComfyUI's cache
middleware would otherwise let browsers cache the miss for an hour
- image-helpers gains fallbackImageSource(): the original is tried once
before a card gives up
Test hygiene: the autotag tests now stub ComfyUI's server module like the
other API test modules, so the module passes when run on its own.
Vito Sansevero
85d1031179