Final: Complete modernization - Option 1 deployment, unified persistence, migration scripts

- Implement Docker image-based deployment (Option 1)
  * Code immutable in image, no volume override
  * Eliminated init-data.sh manual step
  * Simplified deployment process

- Unified persistence in data/ folder
  * Moved nginx.conf and nginx-custom-domains.conf to data/
  * All runtime configs and data in single location
  * Clear separation: repo (source) vs data/ (runtime)

- Archive legacy features
  * Groups blueprint and templates removed
  * Legacy playlist routes redirected to content area
  * Organized in old_code_documentation/

- Added network migration support
  * New migrate_network.sh script for IP changes
  * Regenerates SSL certs for new IP
  * Updates database configuration
  * Tested workflow: clone → deploy → migrate

- Enhanced deploy.sh
  * Creates data directories
  * Copies nginx configs from repo to data/
  * Validates file existence before deployment
  * Prevents incomplete deployments

- Updated documentation
  * QUICK_DEPLOYMENT.md shows 4-step workflow
  * Complete deployment workflow documented
  * Migration procedures included

- Production ready deployment workflow:
  1. Clone & setup (.env configuration)
  2. Deploy (./deploy.sh)
  3. Migrate network (./migrate_network.sh if needed)
  4. Normal operations (docker compose restart)

app/blueprints/playlist.py

@@ -16,25 +16,16 @@ playlist_bp = Blueprint('playlist', __name__, url_prefix='/playlist')
 @playlist_bp.route('/<int:player_id>')
 @login_required
 def manage_playlist(player_id: int):
-    """Manage playlist for a specific player."""
+    """Legacy route - redirect to new content management area."""
     player = Player.query.get_or_404(player_id)
     
-    # Get content from player's assigned playlist
-    playlist_items = []
     if player.playlist_id:
-        playlist = Playlist.query.get(player.playlist_id)
-        if playlist:
-            playlist_items = playlist.get_content_ordered()
-    
-    # Get available content (all content not in current playlist)
-    all_content = Content.query.all()
-    playlist_content_ids = {item.id for item in playlist_items}
-    available_content = [c for c in all_content if c.id not in playlist_content_ids]
-    
-    return render_template('playlist/manage_playlist.html',
-                         player=player,
-                         playlist_content=playlist_items,
-                         available_content=available_content)
+        # Redirect to the new content management interface
+        return redirect(url_for('content.manage_playlist_content', playlist_id=player.playlist_id))
+    else:
+        # Player has no playlist assigned
+        flash('This player has no playlist assigned.', 'warning')
+        return redirect(url_for('players.manage_player', player_id=player_id))
 
 
 @playlist_bp.route('/<int:player_id>/add', methods=['POST'])