Episode advance carried live player state, so the viewer's choice only
survived while every episode could serve it: one episode without the
picked audio or subtitle fell back, and the fallback became the carry for
the rest of the session. The screen now keeps the last explicit audio,
subtitle, and secondary-subtitle choices for its lifetime; automatic
outcomes never overwrite them, so the choice retries on every following
episode and reattaches as soon as a catalog can serve it again.
Audio catches up with the subtitle carry from #1785. The old matcher
required raw language equality (a 'sv' pick never found a 'swe' row) and
otherwise took the first same-language track, flipping a commentary or
alternate-mix pick back to the main mix on every episode. Audio now uses
the same evidence bands as subtitles: bridged language parity is
authoritative, a unique title match vouches for untagged tracks, codec
and channel-count parity only break ties, and an ambiguous catalog
declines to the server's own choice instead of guessing. The synthesized
source descriptor also prefers the row's own title over the display title
that collapses to the bare language.
Episode advance previously sent no audio hint to negotiation at all, so a
transcode baked in the server's default audio no matter what was playing.
Both backends now resolve the carried semantics against the new episode's
streams: Jellyfin sends the resolved AudioStreamIndex, Plex feeds the
transcode decision, an explicit per-part stream id always wins, and a
failed match falls back to the server's pick.
close#1785
* fix(plex): show PGS subtitles when transcoding
Bitmap subtitles (PGS/VOBSUB) disappeared from the menu while transcoding on Plex, leaving only "Off". The MKV transcode already supports them, so embed them in the stream like text subs. Now they show up and can be turned on.
* fix(plex): give bitmap subtitle codecs the right sidecar extension
getSubtitleExtension fell back to .srt for vobsub, pgssub and dvb subs. Map them to .sub/.sup so it stays consistent with isImageSubtitleCodec and any sidecar URL or download uses the correct extension.