Move client key to database with admin UI for key management and QR code generation

- Store client key in SQLite database instead of environment variable
- Add database migration from CLIENT_KEY environment variable to preserve existing keys
- Add admin UI with tabbed interface (Configuration and QR Code tabs)
- Implement QR code generation containing server config (address, port, key) for Android app
- Add functionality to regenerate client key with warning dialog
- Add buttons to download QR code as PNG and copy QR image to clipboard
- Add manual input fields for server address and port configuration
- Update requirements.txt with pyotp and qrcode dependencies

src/app.py

@@ -10,14 +10,14 @@ from controllers.file_controller import (
     cleanup_expired_files, cleanup_abandoned_uploads
 )
 from controllers.admin_controller import (
-    setup_admin, setup_admin_totp, admin_login, admin_dashboard, admin_logout
+    setup_admin, setup_admin_totp, admin_login, admin_dashboard, admin_logout,
+    update_config, regenerate_key
 )
 from views import views
-from models import init_db, migrate_from_json
+from models import init_db, migrate_from_json, migrate_client_key_to_db
 
 app = Flask(__name__)
 app.config['UPLOAD_FOLDER'] = 'tmp/uploads'
-app.config['CLIENT_KEY'] = os.environ.get('CLIENT_KEY', 'default-secret-key')
 app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY', os.urandom(24).hex())
 app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(hours=24)
 
@@ -28,6 +28,7 @@ if not os.path.exists(app.config['UPLOAD_FOLDER']):
 log.i("Initializing database...")
 init_db()
 migrate_from_json()
+migrate_client_key_to_db()
 
 # Run cleanup on startup
 cleanup_expired_files()
@@ -40,12 +41,19 @@ def require_client_key(f):
         if not client_key:
             log.e("No client key provided in request headers")
             return jsonify({'error': 'Missing client key'}), 401
-            
-        expected_key = app.config['CLIENT_KEY']
+
+        # Get expected key from database
+        from models import get_client_key
+        expected_key = get_client_key()
+
+        if not expected_key:
+            log.e("Server configuration error: no client key in database")
+            return jsonify({'error': 'Server configuration error'}), 500
+
         if client_key != expected_key:
             log.e(f"Invalid client key provided. Expected length: {len(expected_key)}, Got length: {len(client_key)}")
             return jsonify({'error': 'Invalid client key'}), 401
-            
+
         log.i("Client key authentication successful")
         return f(*args, **kwargs)
     return decorated_function
@@ -71,6 +79,8 @@ app.route('/admin/setup/totp', methods=['GET', 'POST'], endpoint='setup_admin_to
 app.route('/admin/login', methods=['GET', 'POST'], endpoint='admin_login')(admin_login)
 app.route('/admin', methods=['GET'], endpoint='admin_dashboard')(admin_dashboard)
 app.route('/admin/logout', methods=['GET'], endpoint='admin_logout')(admin_logout)
+app.route('/admin/config', methods=['POST'], endpoint='update_config')(update_config)
+app.route('/admin/regenerate-key', methods=['POST'], endpoint='regenerate_key')(regenerate_key)
 
 # Register frontend views
 app.register_blueprint(views)