processUploadedVideo returned success with thumbnailKey: null when
both the real thumbnail AND the SVG placeholder failed -- a total,
systemic failure (storage backend down, disk full), not a quirk of
one file. On stable, which doesn't have the #845 call-site fallback,
this silently completed the video with no thumbnail at all instead
of the retryable 'failed' status a throw here produces. On main,
the pre-existing #845 fallback already absorbed this exact case
(no behavior change there) -- verified against codex's own
git-blame check of the pre-PR stable code before applying this.
Now throws in that case, restoring the pre-existing "let the caller
mark it failed and retryable" behavior for a genuinely unrecoverable
video, while keeping every partial-failure case (the vast majority)
resolving with whatever succeeded.
Found by codex review.
Paul Nothaft
852bcd1133