Round 6 turned `artifact_may_arrive` into a positive rule, but keyed it to the HLS vocabulary in
general rather than to what THIS session produces: the playlist regex accepted master/index/stream_*
for every session and the `seq == 0` branch accepted any variant token unconditionally. The two argv
branches are disjoint — a single-audio session is given `seg_%d.ts` + `index.m3u8` and no `%v` at
all, so `master.m3u8`, `stream_*.m3u8` and every `seg_<variant>_<n>.ts` are names it can never write,
and vice versa — so each of those was read as "an HLS name, so wait and see" and held a threadpool
worker, plus its pooled DB connection, for the full timeout. That is verbatim the round-5 outage the
route's own comment claims it prevents.
Measured through the real route against a live single-audio session, before: master.m3u8 404 after
30.0s, stream_q7z.m3u8 404 after 30.0s, seg_a0_0.ts / seg_zzzz_0.ts / seg_0_0.ts 404 after 20.1s
each. After, on the running localdev API: 404 in 44-316ms for all of them, while index.m3u8,
seg_0.ts and seg_1.ts still answer 200 — nothing is over-refused.
The session now carries the rendition names its ffmpeg was told to write, and `entry` is derived from
them instead of passed. And "one place" now means the argv BUILDS its patterns from the same
functions the parser reads back (`segment_name("%d", "%v")`, `variant_playlist_name("%v")`): the
layout was still spelled out independently in six places, with `_VIDEO_VARIANT` read by no consumer,
which is the drift that caused round 6's HIGH. A test asserts the argv's own patterns are what those
functions produce, and that every name they expand to is one the guard accepts.
The load-bearing MEASURED comment cited ffmpeg 8.1.1 — the Windows host's. The binary that writes
these files is the API container's 7.1.5; re-measured there, the conclusion holds.
peter
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