Cleanup tag sync

Mirror each person's per-title protect (Keep) and ignore-watch (Dropped) flags onto their Sonarr/Radarr tags, both ways. Rewatch has its own label too. Set each person's tag labels on their card; the Sync now button reconciles all of them against the arr immediately.

• Keep — protect a tagged title from cleanup. Absolute: checked before any rule, nothing overrides it.
• Rewatch — a one-time do-over. Their history for the title is ignored (not wiped) until they finish it again, then the flag clears itself.
• Dropped — ignore this person's watch data for a tagged title, so their half-watched state can't hold it.

A blank label keeps that flag Kustos-only — it isn't pushed to the arr. An arr label for Rewatch is only needed if you also track rewatches as a tag there.