Add marketing service to docker-compose configuration

frontend/Caddyfile.marketing

@@ -0,0 +1,21 @@
+:8020 {
+    # Enable compression
+    encode gzip zstd
+    
+    # Set root to built files
+    root * /usr/share/caddy
+    
+    # Authenticated app served under /app (if needed in future)
+    handle_path /app* {
+        uri strip_prefix /app
+        try_files {path} /index.html
+        file_server
+    }
+    
+    # Marketing site is the public default
+    handle {
+        try_files {path} /marketing.html
+        file_server
+    }
+}
+