Outgoing notifications were bare POSTs with no auth and no way to verify
they came from Tinyforge. They also went out from one global URL only,
even though stages had a notification_url field, and static-site sync
emitted no events at all.
Schema: add notification_url + notification_secret (lazy-generated) to
settings, projects, stages and static_sites. Migrations are additive.
Notifier: SendSigned computes HMAC-SHA256 over the exact body bytes and
sends X-Hub-Signature-256 (GitHub-compatible — receivers built for
GitHub/Gitea/Forgejo verify out of the box). Aux headers
X-Tinyforge-Event/Delivery/Timestamp/Tier are advisory and not signed.
Empty secret => unsigned send for back-compat.
Resolution: deploys fall through stage > project > settings, sites fall
through site > settings. The secret travels with the URL that sourced
it, so any tier can sign even when its parents are unsigned. Site sync
events now actually emit (site_sync_success / site_sync_failure).
API: 12 new endpoints — {GET secret, POST regenerate, POST disable,
POST test} for each of the 4 tiers. SendSyncForTest returns
status_code/latency_ms/signature_sent/delivery_id/response_snippet so
the UI surfaces receiver feedback inline.
UI: shared OutgoingWebhookPanel.svelte fits the existing card aesthetic.
Signing-state pill, secret reveal-on-demand, regenerate/disable behind
ConfirmDialog modals (not inline strips — too easy to misclick), send-
test result card with colour-coded status. Wired into Settings →
Integrations, project edit form, per-stage edit, and per-site detail.
EN + RU i18n.
Tests: round-trip (sender signs, receiver verifies), tampered-body and
wrong-secret rejection, unsigned-send omits header, send-test surfaces
4xx, concurrent fan-out via Drain. Resolver precedence locked for both
deploy and site paths.
Docs: docs/webhooks.md with header reference, verifier snippets in
Node/Python/Go, and a recipe for the service-to-notification-bridge
generic webhook provider.
