A quick answer whose request never reached the route left no trace: a
redirect in front of the app turns ntfy's POST into a GET, which Next
answered 405 before any wide event, and the worker-only and demo-mode
refusals in the proxy wrote nothing either. The proxy now answers a
non-POST on the action path itself with 405 and Allow: POST, and every
refusal it makes there writes one warn line with a reason and the path
without its token. The route's rate-limit refusal carries a reason too.
The regression test sends the action ntfy publishes, in the shape ntfy
sends it, through the real proxy and route against Postgres.
Refs #1203
Marc-André Bombeck