Fix /api/overlay/data 500 error - add null checks for db_manager

- Check if api_bp.db_manager is available before accessing it
- Return overlay_data gracefully if database not available

mbetterclient/web_dashboard/routes.py

@@ -10747,6 +10747,9 @@ def get_overlay_data():
                     if headless_player.result_data and headless_player.result_data.get('match_id'):
                         try:
                             from ..database.models import MatchModel
+                            if not api_bp.db_manager:
+                                logger.warning("Database manager not available for overlay data")
+                                return jsonify(overlay_data)
                             session = api_bp.db_manager.get_session()
                             try:
                                 match = session.query(MatchModel).filter_by(id=headless_player.result_data['match_id']).first()
@@ -10804,6 +10807,9 @@ def get_overlay_data():
                 if current_phase == 'match' and current_match_id:
                     try:
                         from ..database.models import MatchModel
+                        if not api_bp.db_manager:
+                            logger.warning("Database manager not available for match phase data")
+                            return jsonify(overlay_data)
                         session = api_bp.db_manager.get_session()
                         try:
                             match = session.query(MatchModel).filter_by(id=current_match_id).first()