DeadAir copes with hundreds of silences, and retries a failure (#174)

Production's ffmpeg, Debian's 5.1, refused the copy of Brad & Will's
359: "Error initializing bitstream filter: bsf_list". The frames to drop
went to it as between(...)+between(...)+..., which nests a level a term,
and 5.1 takes 100 terms and refuses 200; the 6.1 the tests ran on took
all 520. Summed as a balanced tree the same 520 nest about 10 deep, and
5.1 takes 4000 that way, checked in the production container.

The failure was also stored as the file having no copy, so nothing would
have tried it again after this fix. Failures are now remembered until
the next start instead. The cap on cuts drops to 3500, so the argument
stays under Linux's 128 KiB with frame numbers in the millions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - DeadAir shortens an episode you have opened but not played yet, instead of passing it over as if you had finished it (#173).
+- DeadAir shortens episodes with more than about a hundred long silences, which is most of an hour's conversation, instead of failing on them, and tries a file it failed on again after the next restart (#174).
 - Cover art up to 20 MB is shown, instead of nothing for anything over 5 MB, as for five of the Glass Cannon Network's feeds.
 - Seeking in an episode while many people listen answers in about 10 ms instead of 40, and files stream about four times as fast: each connection now sends what is ready without waiting for the browser to acknowledge the last part.
 - Artwork that could not be fetched is not fetched again for an hour, instead of on every page load, and the server's log says which image it was and why.