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

Dockerfile

@@ -0,0 +1,25 @@
+# Build stage
+FROM oven/bun:1-alpine AS builder
+
+WORKDIR /app
+
+COPY package.json bun.lockb* ./
+RUN bun install --frozen-lockfile
+
+COPY . .
+ARG VITE_API_BASE_URL=http://localhost:5000/api/v1
+ENV VITE_API_BASE_URL=$VITE_API_BASE_URL
+RUN bun run build
+
+# Production stage
+FROM nginx:alpine AS production
+
+COPY --from=builder /app/dist /usr/share/nginx/html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:8080 || exit 1
+
+CMD ["nginx", "-g", "daemon off;"]

docker-compose.yml

@@ -0,0 +1,15 @@
+services:
+  ui:
+    build: .
+    container_name: gatehouse-ui
+    ports:
+      - "8080:8080"
+    environment:
+      - VITE_API_BASE_URL=${VITE_API_BASE_URL:-http://localhost:5000/api/v1}
+    restart: unless-stopped
+    stop_grace_period: 10s
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "10m"
+        max-file: "3"

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";
+    }
+}