Owning a still-running show means you want its new episodes, so it's on the
watchlist without a click. Implemented as a computed default + explicit-override
so it stays correct:
- video_watchlist gains a 'state' column: 'follow' (explicit) | 'mute' (a
tombstone — user un-followed an airing show that's on by default, so the
default must not silently re-add it).
- Effective watchlist (list/state/counts) = explicit follows ∪ library shows
whose status isn't ended/canceled, minus mutes. Computed at READ time, so it
always tracks the library + a show's status — no scanner hook, no re-seeding.
- remove() now writes a mute tombstone (idempotent) instead of deleting; add()
sets state='follow' and clears any mute. Scoped to the active video server.
The existing library-card eye now paints 'watched' on airing shows by default;
clicking mutes, clicking again re-follows.
4 tests updated/added incl. the airing-default + mute + re-follow flow. 80 video
tests green.