Issues a GET to the Python/Flask backend at the bridge-supplied port.
Path under the Flask root (no leading slash) — e.g. 'ping' or 'sessions/abc'.
'ping'
'sessions/abc'
Callback invoked with the parsed JSON body.
Optional
Optional callback for fetch failures. Defaults to console.error.
console.error
Issues a GET to the Python/Flask backend at the bridge-supplied port.