Port the project-webhook routes under /projects/{project}/webhooks to
the Huma /api/v2: list, create, update (events only), delete. There is
no ReadOne — webhooks carry secrets — so no max_permission and no
AutoPatch PATCH; update is PUT only, mirroring v1.
The resource self-registers and is gated by the webhooks.enabled config
flag inside the registrar (RegisterAll runs after config loads). The
write-only secret and basic-auth credentials are cleared from
create/update responses, matching how ReadAll masks them.
cf1f7c3309