Send a test invocation

Sends a real test email from a Primitive-controlled sender to a local-part on one of the org's verified inbound domains. By default the recipient is a synthetic __primitive_function_test+<random>@<domain> address on a domain selected to route to the function. Scoped functions use their scoped domain; fallback functions use a domain that has no enabled domain-scoped endpoint. Pass local_part to override and exercise routing logic that branches on a specific recipient (the common pattern when one function handles multiple inboxes like summarize@ and action@). The function fires through the normal MX delivery path, so reply / send-mail calls from inside the handler against the inbound's email.id work the same as in production. Returns immediately after the send is queued; the invocation appears on the function's invocations list within a few seconds.

Requires that the function is currently deployed. Returns 422 if the function is in pending or failed state, or if the org has no verified inbound domain to receive the test mail. Returns 400 if local_part is set to a value that does not match the local-part character set.