Let a running save or upload be stopped

[CodyCBakerPhD]

A Stop button now stands beside Save/Upload while a delivery runs, so an accidentally long snippet can be called back instead of waiting it out or reloading the page (which loses the video, the marks and the description with it).

What it stops

Stop trips an AbortSignal (new src/lib/interrupt.ts) that every step of the assembly takes, and that the steps between them read:

• Extraction — mediabunny's conversion is cancelled where it stands; an ffmpeg.wasm run tears the worker down, since @ffmpeg/ffmpeg's own signal only rejects the promise and leaves the encode running inside the worker. ensureFfmpeg loads a fresh instance next time (the core is a cached fetch by then).
• Hashing — read at every 16MB chunk boundary, which is the longest uninterruptible stretch a delivery has.
• The pose overlay — read between frames.
• Uploads — each S3 part transfer, plus a check before registering an asset, so a stop does not leave an asset pointing at a blob it was about to abandon.
• Every file handover, centrally, so whatever was just extracted or hashed is dropped rather than saved or sent.

What it reports

A stop is its own outcome, not a failure: a new neutral stopped status class rather than the red err one. The save route says nothing was written; the upload route says how many files had already gone up and stay in the dataset (registered assets are not withdrawn). Either way the card comes back — Upload on offer again, the video and pose swappable — ready for an adjusted selection.

Tests

tests/unit/interrupt.test.ts for the primitives, plus interruption cases in the etag, upload and extract suites, and tests/integration/interrupt.spec.ts, which holds an S3 part transfer open, presses Stop, and checks that nothing was registered and the card is usable again.

Original prompt

We need the ability to do an interruption to reset and adjust during save or upload operation, in case an accidentally long snippet was selected

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Generated by Claude Code

[github-actions]

PR Preview Action v1.8.1
Preview removed because the pull request was closed.
2026-08-29 21:19 UTC

[codecov-commenter]

Codecov Report

❌ Patch coverage is 70.42254% with 21 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/lib/ffmpeg.ts	0.00%	10 Missing ⚠️
src/lib/streaming.ts	0.00%	8 Missing ⚠️
src/lib/extract.ts	75.00%	3 Missing ⚠️

@@            Coverage Diff             @@
##             main      #56      +/-   ##
==========================================
+ Coverage   84.03%   84.32%   +0.29%     
==========================================
  Files          40       41       +1     
  Lines        1810     1850      +40     
  Branches      453      460       +7     
==========================================
+ Hits         1521     1560      +39     
- Misses        289      290       +1     

Files with missing lines	Coverage Δ
src/lib/bundle.ts	93.22% <ø> (ø)
src/lib/datasetDescription.ts	100.00% <ø> (ø)
src/lib/etag.ts	95.18% <100.00%> (+0.30%)	⬆️
src/lib/generatedBy.ts	100.00% <ø> (ø)
src/lib/interrupt.ts	100.00% <100.00%> (ø)
src/lib/s3.ts	100.00% <100.00%> (ø)
src/lib/testInjection.ts	47.15% <ø> (ø)
src/lib/upload.ts	98.59% <100.00%> (+0.08%)	⬆️
src/lib/extract.ts	36.53% <75.00%> (+12.69%)	⬆️
src/lib/streaming.ts	88.43% <0.00%> (-2.38%)	⬇️
... and 1 more

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