refactor(notify): merge Notifier WebService into Notify WebService

- Delete dead Notify Worker (NoOp handler)
- Move 51 source files (endpoints, contracts, services, compat stores)
- Transform namespaces from Notifier.WebService to Notify.WebService
- Update DI registrations, WebSocket support, v2 endpoint mapping
- Comment out notifier-web in compose, update gateway routes
- Update architecture docs, port registry, rollout matrix
- Notifier Worker stays as separate delivery engine container

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/technical/architecture/module-matrix.md

@@ -82,8 +82,8 @@ The solution contains **46 top-level modules** in `src/`. The architecture docum
 | Module | Path | Purpose | WebService | Worker | Storage |
 |--------|------|---------|------------|--------|---------|
 | **JobEngine** | `src/JobEngine/` | Workflow orchestration, scheduling, task execution, pack registry. Includes Scheduler, TaskRunner, PacksRegistry (Sprint 208); renamed from Orchestrator (Sprint 221). | Yes | Yes | PostgreSQL (`orchestrator`, `scheduler`) |
-| **Notify** | `src/Notify/` | Notification toolkit (Email, Slack, Teams, Webhooks) - shared libraries. Boundary preserved with Notifier (Sprint 209). | Library | N/A | N/A |
-| **Notifier** | `src/Notifier/` | Notifications Studio host (WebService + Worker). Boundary preserved with Notify (Sprint 209). | Yes | Yes | PostgreSQL (`notify`) |
+| **Notify** | `src/Notify/` | Unified notification service (shared libraries + merged WebService). Notifier WebService merged into Notify WebService (2026-04-08). | Yes | N/A | PostgreSQL (`notify`) |
+| **Notifier** | `src/Notifier/` | Notifier Worker (delivery engine). WebService merged into Notify (2026-04-08). | N/A | Yes | PostgreSQL (`notify`) |
 | **Timeline** | `src/Timeline/` | Timeline query, event indexing, and replay. Includes TimelineIndexer (Sprint 210). | Yes | No | PostgreSQL |
 | **Replay** | `src/Replay/` | Deterministic replay engine | Yes | No | PostgreSQL |