Implement Phase 2 Frontend and Phase 3 Data Enrichment

- Initialize React+Vite Frontend with Ant Design Dashboard.
- Implement Data Enrichment: ReccoBeats (Audio Features) and Spotify (Genres).
- Update Database Schema via Alembic Migrations.
- Add Docker support (Dockerfile, docker-compose.yml).
- Update README with hosting instructions.

frontend/nginx.conf

@@ -0,0 +1,13 @@
+server {
+    listen 80;
+    location / {
+        root /usr/share/nginx/html;
+        index index.html index.htm;
+        try_files $uri $uri/ /index.html;
+    }
+    location /api/ {
+        proxy_pass http://backend:8000/;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+    }
+}