fix: migrations, auth, providers health check, E2E tests, remove neko-sama

- Add proper Alembic initial migration (0001_initial_schema.py)
- Migrate refresh tokens from JSON file to SQLite (RefreshTokenTable)
- Remove Neko-Sama provider entirely (redirects to Gupy, not a host)
- Fix provider health check always showing UNKNOWN
  - Run check_all_health() on startup
  - Fix POST /providers/health/check background task bug
  - Add HTMX refresh after manual health check trigger
- Fix anime search relevance scoring with MIN_RELEVANCE_THRESHOLD=0.5
- Replace bare 'except:' with 'except Exception:' across codebase
- Add Playwright E2E test suite (12 tests, auth setup, helpers)
- Fix toast container blocking clicks via pointer-events: none
- Remove obsolete Jest/Vite test files and config
- Clean up obsolete test_watchlist scripts
- Update sonarr model comment for active providers

test_watchlist.py

@@ -41,7 +41,7 @@ async def test_watchlist_manager():
     )
 
     try:
-        item = watchlist_manager.create(test_user, item_data)
+        item = watchlist_manager.add(test_user, item_data)
         print(f"   ✅ Item created: {item.id}")
         print(f"   Title: {item.anime_title}")
         print(f"   Status: {item.status}")
@@ -127,8 +127,8 @@ async def test_scheduler():
 
     print("\n2. Testing scheduler status...")
     try:
-        status = auto_download_scheduler.get_status()
-        print(f"   ✅ Scheduler status: running={status['running']}")
+        running = auto_download_scheduler.is_running()
+        print(f"   ✅ Scheduler status: running={running}")
     except Exception as e:
         print(f"   ❌ Status failed: {e}")
         return False
@@ -136,20 +136,18 @@ async def test_scheduler():
     print("\n3. Testing scheduler start/stop...")
     try:
         # Start scheduler
-        await auto_download_scheduler.start()
+        auto_download_scheduler.start()
         print("   ✅ Scheduler started")
 
-        status = auto_download_scheduler.get_status()
-        if not status['running']:
+        if not auto_download_scheduler.is_running():
             print("   ❌ Scheduler not running after start")
             return False
 
         # Stop scheduler
-        await auto_download_scheduler.stop()
+        auto_download_scheduler.stop()
         print("   ✅ Scheduler stopped")
 
-        status = auto_download_scheduler.get_status()
-        if status['running']:
+        if auto_download_scheduler.is_running():
             print("   ❌ Scheduler still running after stop")
             return False