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

app/providers_manager.py

@@ -10,7 +10,6 @@ from datetime import datetime
 from app.downloaders.generic_scraper import GenericScraper
 from app.downloaders.anime_sites import (
     AnimeSamaDownloader,
-    NekoSamaDownloader,
     AnimeUltimeDownloader,
     VostfreeDownloader,
     FrenchMangaDownloader,
@@ -58,7 +57,6 @@ class ProvidersManager:
         """Load hardcoded Python providers"""
         provider_classes = [
             ("anime-sama", AnimeSamaDownloader, ANIME_PROVIDERS),
-            ("neko-sama", NekoSamaDownloader, ANIME_PROVIDERS),
             ("anime-ultime", AnimeUltimeDownloader, ANIME_PROVIDERS),
             ("vostfree", VostfreeDownloader, ANIME_PROVIDERS),
             ("french-manga", FrenchMangaDownloader, ANIME_PROVIDERS),
@@ -130,10 +128,23 @@ class ProvidersManager:
                     return 200 <= response.status_code < 400
             elif hasattr(scraper, "search_anime"):
                 results = await scraper.search_anime("One Piece", lang="vostfr")
-                return len(results) > 0
+                # Validate that results actually match the query
+                if not results:
+                    return False
+                for r in results:
+                    title = (r.get("title") or "").lower()
+                    if "one" in title or "piece" in title:
+                        return True
+                return False
             elif hasattr(scraper, "search"):
                 results = await scraper.search("One Piece")
-                return len(results) > 0
+                if not results:
+                    return False
+                for r in results:
+                    title = (r.get("title") or "").lower()
+                    if "one" in title or "piece" in title:
+                        return True
+                return False
             return False
         except Exception as e:
             logger.error(