A manual safety-net for the auto-promoter: queues episodes that have ALREADY
aired, are missing, and aren't yet on the wishlist. Upcoming episodes are left
alone (the calendar promotes them once they air), so it's a no-op on the current/
future weeks and useful when you page back to a past one.
- calendar_upcoming now returns the show's tmdb_id.
- /wishlist/check accepts {shows:[...]} -> by_show membership (db.wishlist_keys_
for_shows), so the button only counts/adds what's genuinely not yet queued.
- Calendar: computes aired-missing (air_date < today, !has_file), checks wishlist
membership, shows 'Add N missing to wishlist' when there's net-new; click groups
by show -> /wishlist/add, toasts, fires soulsync:video-wishlist-changed, recomputes.
Tests: +2 (wishlist_keys_for_shows, /wishlist/check by_show). Backend: 100 passed.