Run a backend function of an owned app exactly like the HTTP route and return its status and JSON

Run a backend function of an owned app exactly like the HTTP route and return its status and JSON. caller='owner' runs as the app owner; caller='anonymous' first evaluates the function policy as a public visitor and returns the 401/403 decision without running when access would be denied. Use it to verify a function (secrets, outbound calls, policy) before wiring it into the app.