Fix entity-based migrations that crash on missing columns

MusicVideosUpdate and AddEpisodicGenres migrations used TypeORM
entity classes which reference columns that don't exist at their
migration timestamp (e.g. trailer_old, later entity fields).
Rewrote both to use raw SQL INSERT/UPDATE statements.

Also bumped CACHEBUST to v3 to force backend image rebuild.

Co-authored-by: Cursor <cursoragent@cursor.com>

docker-compose.yml

@@ -44,12 +44,12 @@ services:
 
   # ── Backend API (NestJS) ────────────────────────────────────
   api:
-    image: indeehub-api:v2
+    image: indeehub-api:v3
     build:
       context: ./backend
       dockerfile: Dockerfile
       args:
-        CACHEBUST: "2"
+        CACHEBUST: "3"
     restart: unless-stopped
     environment:
       # ── Core ─────────────────────────────────────────────
@@ -177,12 +177,12 @@ services:
 
   # ── FFmpeg Transcoding Worker ───────────────────────────────
   ffmpeg-worker:
-    image: indeehub-ffmpeg:v2
+    image: indeehub-ffmpeg:v3
     build:
       context: ./backend
       dockerfile: Dockerfile.ffmpeg
       args:
-        CACHEBUST: "2"
+        CACHEBUST: "3"
     restart: unless-stopped
     environment:
       ENVIRONMENT: production