build(docker): add multi-stage Dockerfile with nginx and docker-compose

Add containerization support for production deployment:
- Multi-stage Dockerfile using Bun for build and nginx for serving
- docker-compose.yml for container orchestration
- nginx.conf with gzip compression, caching headers, and security headers

nginx.conf

@@ -0,0 +1,29 @@
+server {
+    listen 8080;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    gzip on;
+    gzip_vary on;
+    gzip_min_length 1024;
+    gzip_proxied any;
+    gzip_types text/plain text/css text/xml text/javascript application/javascript application/json application/xml;
+
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-XSS-Protection "1; mode=block" always;
+
+    location = /index.html {
+        add_header Cache-Control "no-cache, no-store, must-revalidate";
+    }
+}