feat(cli): 引入 citty CLI，迁移改为显式 ./server migrate

- 顶层新增 bin.ts 作为编译入口，citty 懒加载 src/cli/ 下子命令
- src/cli/serve.ts 通过 _serve-nitro.mjs 桥接启动 Nitro（规避
  .output/server/index.mjs 顶层 serve(...) 的副作用导入）
- src/cli/migrate.ts 显式跑 drizzle migrate；env / drizzle 都在 run()
  里 await import，避免 citty --help 遍历 subCommands 时触发 env 校验
- compile.ts 入口切到 bin.ts；移除 src/server/plugins/migrate.ts
  与 vite.config.ts 中的启动时自动迁移
- compose.yaml 新增一次性 migrate 服务，app depends_on
  service_completed_successfully，保证迁移先行再起服
- tsconfig 排除 .output / out；AGENTS.md 补充 CLI 与部署规约

package.json

@@ -5,6 +5,7 @@
   "type": "module",
   "scripts": {
     "build": "bunx --bun vite build",
+    "cli": "bun bin.ts",
     "compile": "bun compile.ts",
     "compile:darwin": "bun run compile:darwin:arm64 && bun run compile:darwin:x64",
     "compile:darwin:arm64": "bun compile.ts --target bun-darwin-arm64",
@@ -34,6 +35,7 @@
     "@tanstack/react-router": "^1.168.23",
     "@tanstack/react-router-ssr-query": "^1.166.11",
     "@tanstack/react-start": "^1.167.43",
+    "citty": "^0.2.2",
     "drizzle-orm": "0.45.2",
     "drizzle-zod": "^0.8.3",
     "postgres": "^3.4.9",