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

src/server/plugins/migrate.ts

@@ -1,17 +0,0 @@
-import { drizzle } from 'drizzle-orm/postgres-js'
-import { migrate } from 'drizzle-orm/postgres-js/migrator'
-import { env } from '@/env'
-
-export default async () => {
-  if (import.meta.dev) return
-
-  const db = drizzle({ connection: { url: env.DATABASE_URL, max: 1 } })
-
-  try {
-    console.log('Applying migrations...')
-    await migrate(db, { migrationsFolder: './drizzle' })
-    console.log('Migrations applied successfully.')
-  } finally {
-    await db.$client.end()
-  }
-}