feat: Complete watchlist & auto-download system with UI

Implement comprehensive watchlist system with automatic episode detection
and downloading. Features include per-user watchlists, scheduler-based
periodic checks, and a modern web UI.

**Backend Components:**
- WatchlistManager: JSON-based storage with multi-tenant support
- EpisodeChecker: Detects and downloads new episodes automatically
- AutoDownloadScheduler: APScheduler-based periodic task execution
- Complete REST API for CRUD operations and scheduler control

**Frontend Components:**
- Modern watchlist page with dark theme and animations
- Real-time status updates and progress tracking
- Scheduler controls with next-run display
- Add anime directly from search results

**Models & Configuration:**
- WatchlistItem with status, quality, and auto-download settings
- WatchlistSettings for global configuration
- Per-user statistics and provider tracking

**API Endpoints:**
- GET/POST /api/watchlist - List and add items
- PUT/DELETE /api/watchlist/{id} - Update and delete
- POST /api/watchlist/{id}/check - Manual check trigger
- POST /api/watchlist/check-all - Check all due items
- GET/PUT /api/watchlist/settings - Global settings
- GET /api/watchlist/stats - Statistics
- GET/POST /api/watchlist/scheduler/* - Scheduler control

**Configuration Files:**
- config/watchlist.json - User watchlist data
- config/watchlist_settings.json - Global settings

Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

static/js/anime-details.js

@@ -62,26 +62,27 @@ async function searchAnimeDetails(query, malId = null) {
             const providersData = await getProvidersInfo();
 
             // Build results HTML
-            streamingHtml = `
-                <div class="streaming-results-header">
+            const streamingParts = [
+                `<div class="streaming-results-header">
                     <h3>🎬 Résultats de streaming</h3>
                 </div>
-                <div class="search-results" style="margin-top: 20px;">
-            `;
+                <div class="search-results" style="margin-top: 20px;">`
+            ];
 
-            // Display results from each provider
+            // Display results from each provider - render all cards in parallel
             for (const [providerId, results] of Object.entries(streamingData.value.results)) {
                 if (results && results.length > 0) {
                     const provider = providersData.anime_providers[providerId];
 
-                    results.forEach((anime) => {
-                        // Use the same renderAnimeCard function from anime.js for consistency
-                        streamingHtml += renderAnimeCard(anime, providerId, provider, 'vostfr');
-                    });
+                    // Render all cards for this provider
+                    const cardPromises = results.map((anime) => renderAnimeCard(anime, providerId, provider, 'vostfr'));
+                    const cards = await Promise.all(cardPromises);
+                    streamingParts.push(...cards);
                 }
             }
 
-            streamingHtml += '</div>';
+            streamingParts.push('</div>');
+            streamingHtml = streamingParts.join('');
         }
 
         // Display results
@@ -149,12 +150,12 @@ async function getProviderSearchResults(query) {
         }
 
         // Build results HTML
-        let html = `
-            <div class="streaming-results-header">
+        const htmlParts = [
+            `<div class="streaming-results-header">
                 <h3>🎬 Résultats de streaming</h3>
             </div>
-            <div class="search-results" style="margin-top: 20px;">
-        `;
+            <div class="search-results" style="margin-top: 20px;">`
+        ];
 
         // Display results from each provider
         for (const [providerId, results] of Object.entries(data.results)) {
@@ -162,16 +163,16 @@ async function getProviderSearchResults(query) {
                 const providersData = await getProvidersInfo();
                 const provider = providersData.anime_providers[providerId];
 
-                results.forEach((anime, index) => {
-                    // Use the same renderAnimeCard function from anime.js for consistency
-                    html += renderAnimeCard(anime, providerId, provider, 'vostfr');
-                });
+                // Render all cards for this provider in parallel
+                const cardPromises = results.map((anime) => renderAnimeCard(anime, providerId, provider, 'vostfr'));
+                const cards = await Promise.all(cardPromises);
+                htmlParts.push(...cards);
             }
         }
 
-        html += '</div>';
+        htmlParts.push('</div>');
 
-        return html;
+        return htmlParts.join('');
 
     } catch (error) {
         console.error('Error getting provider search results:', error);