feat: add Docker deployment — multi-stage build + nginx SPA serving

nginx.conf

@@ -0,0 +1,24 @@
+server {
+    listen 80;
+    server_name _;
+
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Gzip compression
+    gzip on;
+    gzip_types text/plain text/css application/javascript application/json image/svg+xml;
+    gzip_min_length 1024;
+
+    # Cache static assets aggressively
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff2?)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+        try_files $uri =404;
+    }
+
+    # SPA fallback — all routes serve index.html
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+}