Add Spotify integration with album streaming links

- Implement Spotify Web API integration for album streaming links
- Add extract_spotify_urls.py script for automated Spotify URL extraction
- Create spotify_urls_mapping.json with sample album mappings (20 albums)
- Update album cards to include both Wikipedia and Spotify links
- Add Spotify-branded styling with official green color and logo
- Implement smart fallback to Spotify search for unmapped albums
- Add responsive design for mobile with stacked link layout
- Update README with comprehensive feature documentation

Features:
• Each album now has "Listen on Spotify" link with Spotify icon
• Spotify links use official Spotify green branding
• Theme-aware styling adapts to dark/light themes
• Mobile-optimized layout with vertical link stacking
• Production-ready script for extracting all 500 album URLs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

styles.css

@@ -729,6 +729,10 @@ body {
     text-align: center;
     padding-top: 1rem;
     border-top: 1px solid #eee;
+    display: flex;
+    gap: 1rem;
+    justify-content: center;
+    flex-wrap: wrap;
 }
 
 .wikipedia-link {
@@ -754,6 +758,38 @@ body {
     transform: translateY(0);
 }
 
+.spotify-link {
+    display: inline-block;
+    color: #1db954; /* Spotify green */
+    text-decoration: none;
+    font-size: 0.9rem;
+    font-weight: 500;
+    padding: 0.5rem 1rem;
+    border-radius: 20px;
+    background: rgba(29, 185, 84, 0.1);
+    transition: all 0.3s ease;
+}
+
+.spotify-link:hover {
+    background: rgba(29, 185, 84, 0.2);
+    opacity: 0.8;
+    transform: translateY(-1px);
+}
+
+.spotify-link:active {
+    transform: translateY(0);
+}
+
+/* Dark theme adjustments for Spotify link */
+[data-theme="dark"] .spotify-link,
+[data-theme="gruvbox"] .spotify-link,
+[data-theme="gruvbox-dark"] .spotify-link,
+[data-theme="dracula"] .spotify-link,
+[data-theme="nord"] .spotify-link,
+[data-theme="solarized"] .spotify-link {
+    color: #1ed760; /* Slightly brighter Spotify green for dark themes */
+}
+
 
 /* Loading and error states */
 .loading {
@@ -918,4 +954,9 @@ body {
         opacity: 1;
         transform: scale(1);
     }
+    
+    .album-links {
+        flex-direction: column;
+        gap: 0.5rem;
+    }
 }