fix(video): move idx_movies_collection to _POST_INDEXES (broke DB init)

The new index on movies.tmdb_collection_id was in video_schema.sql, which executescript runs
BEFORE _ensure_columns adds the column on existing DBs — so 'CREATE INDEX ... ON
movies(tmdb_collection_id)' failed with 'no such column' and the whole video DB init aborted
(500s on every /api/video/* call). Moved the index to _POST_INDEXES (runs after the ALTERs),
matching the pattern the code comments already prescribe. The CREATE TABLE columns stay (fresh
DBs) + the ALTER migration stays (existing DBs); only the index moved.

database/video_database.py

@@ -302,6 +302,9 @@ class VideoDatabase:
         "ON video_wishlist(source_id) WHERE kind = 'video'",
         "CREATE INDEX IF NOT EXISTS idx_video_wishlist_channel "
         "ON video_wishlist(parent_source_id) WHERE kind = 'video'",
+        # Index on movies.tmdb_collection_id — a migration-added column, so it must be
+        # created AFTER _ensure_columns (the schema executescript runs before the ALTERs).
+        "CREATE INDEX IF NOT EXISTS idx_movies_collection ON movies(tmdb_collection_id)",
     )
 
     @classmethod

database/video_schema.sql

@@ -98,8 +98,9 @@ CREATE TABLE IF NOT EXISTS movies (
     updated_at           TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
 );
 CREATE INDEX IF NOT EXISTS idx_movies_tmdb       ON movies(tmdb_id);
-CREATE INDEX IF NOT EXISTS idx_movies_collection ON movies(tmdb_collection_id);
 CREATE INDEX IF NOT EXISTS idx_movies_monitored  ON movies(monitored, has_file);
+-- NOTE: idx on tmdb_collection_id (a migration-added column) lives in _POST_INDEXES,
+-- not here — this schema runs BEFORE the ALTER that adds the column on upgraded DBs.
 CREATE INDEX IF NOT EXISTS idx_movies_release    ON movies(release_date);
 -- Upsert/stale-removal key: the server's native id. Multiple NULLs are allowed
 -- (wishlist items not yet on a server), so this never blocks non-server rows.