feat(NFO): add TMDB search fallback with alt_titles support

- New _search_with_fallback() method tries multiple strategies:
  1. Primary query with year filter (de-DE locale)
  2. Alternative titles with ja-JP / en-US locales
  3. English search (en-US)
  4. Search without year constraint
  5. Punctuation-normalized query
- create_nfo() accepts new alt_titles param for Japanese/title fallback
- Better match rate for anime with non-English titles

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docs/DEVELOPMENT.md

@@ -143,3 +143,35 @@ await client.close()  # May not be called if exception raised earlier
 **Verification:**
 - Missing context manager usage triggers `__del__` warning on garbage collection
 - Integration tests verify no "Unclosed client session" errors in logs
+
+### Scheduler Persistence and Recovery
+
+APScheduler stores jobs in `data/scheduler.db` (SQLite) so they survive process restarts:
+
+```python
+from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
+
+jobstores = {
+    "default": SQLAlchemyJobStore(url="sqlite:///./data/scheduler.db"),
+}
+scheduler = AsyncIOScheduler(jobstores=jobstores)
+```
+
+**Grace period:** `misfire_grace_time=3600` (1 hour). If server is down at scheduled time and restarts within 1 hour, missed job runs automatically via APScheduler coalesce behavior.
+
+**Startup recovery:** On `start()`, scheduler loads persisted jobs from DB. APScheduler handles missed jobs internally when `coalesce=True`.
+
+**Health endpoint:** `GET /health` returns `scheduler_next_run` and `scheduler_last_run` for external monitors (Uptime Kuma, Prometheus, etc.).
+
+**If server is down >1 hour:** No automatic recovery. Manual trigger via `POST /api/scheduler/trigger-rescan` or wait for next scheduled run.
+
+### Troubleshooting Development Issues
+
+#### Scheduler missed a run
+
+1. Server was down at scheduled time (03:00 UTC by default).
+2. Check `data/scheduler.db` exists — if not, jobs are not persisted.
+3. If server was down >1 hour, missed job is dropped (misfire window exceeded).
+4. Trigger manually: `POST /api/scheduler/trigger-rescan`
+5. Monitor next run: `GET /health` → `scheduler_next_run`
+6. If problem repeats, increase `misfire_grace_time` in `scheduler_service.py`.