Replaces the one-shot guarded POST with the maintainer's intended end-state: the
webhook node now references a CONFIGURED webhook subscription (Settings →
Webhooks) and enqueues a real webhook_deliveries row via
webhookService.enqueueForWebhook. Delivery then rides the existing worker
pipeline, inheriting — not reimplementing — per-delivery SSRF re-validation
(validateExternalUrl / GHSA-wmjx-pc37-272r), HMAC signing with the
subscription's secret, retry/backoff, and the deliveries audit log.
- webhookService.enqueueForWebhook(webhookId, eventType, data): enqueue for one
active subscription, bypassing fire()'s event-type matching. No schema change.
- webhook action: config.webhookId; unset/missing/inactive → observable skip;
dry-run does not enqueue. event_type = workflow.<trigger>.
- Editor: webhook node config is now a subscription dropdown (was a raw URL),
fed by the admin webhooks list, with a hint pointing to Settings → Webhooks.
- EN/DE strings; test asserts enqueue + dry-run no-op + inactive skip.