The subtitles resource is purely a watch-tracking ping (it returns no real
subtitles), so advertising it always made Stremio hit the addon on every
playback even for users with no tracking. Gate it in the manifest on the
same condition the route uses, and fold it into the manifest fingerprint so
the existing Reinstall Required banner fires when tracking is toggled.

Also fix the subtitle route gate, which checked only 4 of the 5 trackers and
silently skipped users with only PublicMetaDB tracking enabled.