Architektur: Craftvia-Domänenmodell, Verträge und Team-Schnitte

- Migration 0002_craftvia_domain: 27 Fachtabellen inkl. RLS (enable_tenant_rls)
- TENANT_MODELS (db.ts, backup/topology.ts) um alle Fachmodelle ergänzt
- moduleGuard liefert DB-autoritative Rechte; ServiceCtx für Domänen-Services
- Verträge: Statusmaschine, Events, Nummernkreise, Sichtbarkeits-Scopes,
  Job-Queues + Worker, KI-Provider-Interfaces, Sync-Envelope
- docs/craftvia/ARCHITEKTUR.md mit Lanes, Ownership und DoD

Gate: tsc, lint, build, 22/22 Tests grün.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/server/services/notifications/handle-event.ts

@@ -0,0 +1,10 @@
+import type { DomainEvent } from "@/lib/events";
+import type { ServiceCtx } from "@/server/services/context";
+
+/**
+ * Placeholder — replaced by lane "notifications" (recipient rules, in-app Notification rows,
+ * e-mail via the mail queue). Keeps emitEvent() callable for all other lanes meanwhile.
+ */
+export async function handleEvent(_ctx: ServiceCtx, _event: DomainEvent): Promise<void> {
+  // intentionally empty
+}