HTTPS/CORS improvements: Enable CORS for player connections, secure session cookies, add certificate endpoint, nginx CORS headers

app/app.py

@@ -52,6 +52,18 @@ def create_app(config_name=None):
     # Configure Flask-Login
     configure_login_manager(app)
     
+    # Initialize CORS for player API access
+    from app.extensions import cors
+    cors.init_app(app, resources={
+        r"/api/*": {
+            "origins": ["*"],
+            "methods": ["GET", "POST", "OPTIONS", "PUT", "DELETE"],
+            "allow_headers": ["Content-Type", "Authorization"],
+            "supports_credentials": True,
+            "max_age": 3600
+        }
+    })
+    
     # Register components
     register_blueprints(app)
     register_error_handlers(app)