Cleanup: remove unused code, add CI/CD workflow

- Remove flask-sse, Redis (unused)
- Remove ImageService, file_utils (unused)
- Remove /download-posters route (frontend handles download client-side)
- Remove LETTERBOXD_API_URL, secure_filename (dead imports)
- Fix duplicate TMDBService instantiation
- Simplify config.py (remove REDIS_URL)
- Fix gunicorn user home dir for control socket
- Add .gitignore for __pycache__
- Add .gitea/workflows/deploy.yml for tag-based CI/CD

src/services/tmdb_service.py

@@ -24,7 +24,7 @@ class TMDBService:
         return None
     
     def get_movie_posters(self, movie_id):
-        url = f"{self.base_url}/movie/{movie_id}/images?include_image_language=en,fr,null"
+        url = f"{self.base_url}/movie/{movie_id}/images?include_image_language=en,fr,ja,null&language=null"
         headers = {
             "accept": "application/json",
             "Authorization": f"Bearer {self.access_token}"