DevOps: Add PM2 deployment scripts

Add complete PM2 deployment solution:
- pm2.config.js: Dynamic path configuration
- pm2.sh: One-click management script
- PM2_DEPLOYMENT.md: Deployment guide
Co-Authored-By: tinkle-community <tinklefund@gmail.com>

pm2.config.js

@@ -0,0 +1,41 @@
+const path = require('path');
+
+module.exports = {
+  apps: [
+    {
+      name: 'nofx-backend',
+      script: './nofx',
+      cwd: __dirname, // 使用当前目录（配置文件所在目录）
+      interpreter: 'none', // 不使用解释器，直接执行二进制文件
+      instances: 1,
+      autorestart: true,
+      watch: false,
+      max_memory_restart: '500M',
+      env: {
+        NODE_ENV: 'production'
+      },
+      error_file: './logs/backend-error.log',
+      out_file: './logs/backend-out.log',
+      log_date_format: 'YYYY-MM-DD HH:mm:ss Z',
+      merge_logs: true
+    },
+    {
+      name: 'nofx-frontend',
+      script: 'npm',
+      args: 'run dev',
+      cwd: path.join(__dirname, 'web'), // 动态拼接 web 目录
+      instances: 1,
+      autorestart: true,
+      watch: false,
+      max_memory_restart: '300M',
+      env: {
+        NODE_ENV: 'development',
+        PORT: 3000
+      },
+      error_file: './logs/frontend-error.log',
+      out_file: './logs/frontend-out.log',
+      log_date_format: 'YYYY-MM-DD HH:mm:ss Z',
+      merge_logs: true
+    }
+  ]
+};