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

templates/components/settings_section.html

@@ -93,7 +93,8 @@
     <div class="settings-card card" style="padding: 25px; background: var(--bg-card); border-radius: var(--card-radius); border: 1px solid rgba(255,255,255,0.05);">
         <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px;">
             <h3 style="margin: 0; color: var(--primary);">Disponibilite des Fournisseurs</h3>
-            <button class="btn btn-secondary btn-small" hx-post="/api/providers/health/check" hx-swap="none">
+            <button class="btn btn-secondary btn-small" hx-post="/api/providers/health/check" hx-swap="none"
+                    hx-on::after-request="htmx.trigger('#tab-settings > div', 'refresh-settings')">
                 <i class="fas fa-sync-alt"></i> Forcer verification
             </button>
         </div>

templates/components/toast_container.html

@@ -33,6 +33,10 @@
     display: flex;
     flex-direction: column;
     gap: 10px;
+    pointer-events: none;
+}
+.toast {
+    pointer-events: auto;
 }
 .toast {
     min-width: 250px;