Add .env.production.example as setup guide

.env.production.example

@@ -0,0 +1,36 @@
+# ─────────────────────────────────────────────────────────────
+# BackOne Deep Package Inspection - Production Environment
+# Copy this file to .env.production and fill in your values
+# ─────────────────────────────────────────────────────────────
+
+NODE_ENV=production
+
+# --- API Credentials ---
+BACKONE_DPI_API_KEY=your_dpi_api_key_here
+BACKONE_API_KEY=your_api_key_here
+BACKONE_ORG_UUID=your_org_uuid_here
+BACKONE_SITE_UUID=your_site_uuid_here
+BACKONE_SITE_UUIDS=site_uuid_1,site_uuid_2
+BACKONE_INFORMATICS_BASE_URL=https://your-api-server.example.com/api/v1
+
+# --- MongoDB ---
+MONGODB_URI=mongodb://user:password@your-mongodb-host:27017/your_database
+
+# --- Backend ---
+BACKEND_PORT=3001
+
+# --- Proxy Settings ---
+PROXY_COLLECT_MODE=all
+PROXY_CRON_SCHEDULE=*/10 * * * *
+PROXY_PORT=4010
+PROXY_AGENT_DELAY_MS=5000
+
+# --- JWT Secret (generate a strong random string) ---
+JWT_SECRET=your_jwt_secret_here
+
+# --- CORS (comma-separated list of allowed frontend origins) ---
+ALLOWED_ORIGINS=https://your-frontend-domain.example.com
+
+# --- Next.js Frontend ---
+# URL where the backend API is accessible from the frontend
+NEXT_PUBLIC_API_URL=https://your-backend-domain.example.com