* add sub stream recording with adaptive quality playback
Optionally record a second, lower bitrate stream alongside the main
recording stream via a `record_sub` input role and `record.sub` config block, with its own retention windows.
Recordings rows now carry the stream type plus the media details needed to serve both streams from one manifest: video codec, audio presence, audio codec and rate, and a record-time keyframe index.
Playback resolves coverage across both streams and merges them into a single VOD sequence, falling back to a discontinuity manifest with per-clip init segments when the media signatures differ. The player exposes a quality selector, and an auto governor picks the stream from stall time, bandwidth, codec support, and the save-data hint.
* fix tests and i18n
* update e2e mock data to remove deprecated fields
* remove scream audio label
scream was never mapped to anything in frigate's custom labelmap, yell is used everywhere
* document common audio labels
* deprecate ffmpeg 5
* language tweak
* add field message to recommend presets instead of manual hwaccel args
* add guidance to docs on choosing a detect fps
* basic e2e frontend test framework
* improve mock data generation and add test cases
* more cases
* add e2e tests to PR template
* don't generate mock data in PR CI
* satisfy codeql check
* fix flaky system page tab tests by guarding against crashes from incomplete mock stats
* reduce local test runs to 4 workers to match CI
