Increase the upload size limit

Addresses #397

zwift_offline.py

@@ -153,7 +153,7 @@ def make_dir(name):
         f.write(os.urandom(16))
 with open(SECRET_KEY_FILE, 'rb') as f:
     app.config['SECRET_KEY'] = f.read()
-app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024
+app.config['MAX_CONTENT_LENGTH'] = 4 * 1024 * 1024  # A typical .fit file with power, cadence, and heartrate data recorded in December 2024 is approximately 1.3 MB / 4 hours.
 db = SQLAlchemy()
 db.init_app(app)