test: cover NATS bridge + Todoist scheduler; ADR-0010

- bus.test.ts: 4 cases for the new onPublish hook contract
- nats.test.ts: stream creation idempotency + JSON publish bridge
- scheduler.test.ts: startup delay, fan-out, per-user failure isolation
- ADR-0010 documents the bridge-don't-replace decision and the
  Todoist scheduler isolation, plus open follow-ups (#98 ml/serving
  consumer, #54 protobuf migration, graceful shutdown, metrics)
- README/overview/services README reflect the bridged event substrate
- CLAUDE.md gains a "don't nats.publish() directly" rule
- .env.example documents NATS_URL + TODOIST_SYNC_INTERVAL_MS

Verified in deployment 2026-04-18: api -> nats bridge connects on
boot, signals + feedback streams created, scheduler tick logs
"todoist sync: 1 ok, 0 failed (1 users)" within 10s. Closes #21, #22.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/architecture/overview.md

@@ -15,7 +15,7 @@
 | `auth` | TS | OAuth (Google; Apple in M1), sessions, JWT | identities, sessions | Node monolith |
 | `profile` | TS | user profile, preferences, consents | profiles | Node monolith |
 | `integrations` | TS | third-party connectors, token vault, signal fetch | credentials, cursors | Node monolith |
-| `events` | TS | event-bus abstraction + durable log (M1) | signal store | Node monolith (in-proc emitter) |
+| `events` | TS | event-bus abstraction + durable log | signal store | Node monolith (in-proc emitter, bridges to NATS JetStream when `NATS_URL` set) |
 | `recommender` | TS | orchestration: candidates → policy → tip; feedback sink | tip history | Node monolith |
 | `notifier` | TS | push/email delivery, quiet hours, dedupe | delivery log | Node monolith (web push in M1) |
 | `ml/serving` | Python | online scoring for policies/models | — (stateless) | **separate process** |