<video basename>.<ext> or <video basename>.<qualifiers>.<ext> (case-insensitive), <ext> in srt, ass, ssa, vtt, where every qualifier is a language (en, eng, fre, pt-BR, English) or a flag (forced, sdh, cc, hi, default, full, signs, songs):

Movie.srt, Movie.eng.srt, Movie.en.srt, Movie.fr.forced.srt → sidecars of Movie.mkv
Movie.Extended.eng.srt → not a sidecar of Movie.mkv

Language: the qualifier when present, else a franc-min sniff of the subtitle text (timecodes and ASS markup stripped), else und. Codes are ISO 639-2/B (fre, ger, chi), normalised the same way meta-watch does. hi means hearing-impaired, not Hindi (use hin).

What it writes (METADATA_KEYS.md §8)

Record	Key	Value
video	`subtitles/<lang3>/<subCid>`	`"true"`
video	`subtitleLanguages/<lang3>`	`"true"` (not for `und`)
subtitle	`videos/<videoCid>`	`"true"`
subtitle	`subtitleLanguage`	`<lang3>` (not for `und`)

Each run writes its own record in full and the other record only if it already exists, so the result is the same whichever file the watcher processes first. Writes are one PATCH of only-new keys; a failed write fails the task. Legacy comma-joined subtitles / videos scalars are migrated to the key-set.

File access

WebDAV only (the container has no /files mount): directory listing, size and bytes come from the meta-core that drove the task (/urls → webdavUrlInternal; WEBDAV_URL overrides). CIDs are midhash256 computed from one ≤1 MiB Range read.

Tests

pnpm install && (cd node_modules/@metazla/filename-tools && pnpm install && pnpm run build) && pnpm test
./test.sh   # in Docker

License

MIT