feat(db): 0000 站点域——sites/site_config_revisions + 唯一约束

drizzle-kit 首个迁移从 0000 起编号（计划文案写 0001，以实际产出为准）。
迁移文件 + meta/_journal.json + snapshot 一并入库。

Co-Authored-By: Claude Code <noreply@anthropic.com>

tests/integration/db.sites.test.ts

@@ -0,0 +1,26 @@
+// 站点域集成测试：约束在真 PG 上生效（唯一键、复合唯一键）。
+// 简易内联版——Task 13 收敛为公共 helper；本任务只需连库即可（getDb 从 apps/api 源码导入）。
+// 生命周期纪律：随机 key 插入 + finally 清理，可重复运行不残留脏数据。
+import { describe, it, expect } from 'vitest'
+import { getDb } from '../../apps/api/src/db/client.js'
+
+describe('站点域约束', () => {
+  it('sites.key 唯一；site_config_revisions (site_id,version) 唯一', async () => {
+    const db = getDb()
+    const key = `fixture-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`
+    const r = (await db.execute(`insert into sites (id, key, name, default_locale, production_origin)
+      values (gen_random_uuid(), '${key}', 'Fixture', 'en', 'https://fixture.example') returning id`)) as any
+    const siteId = r[0].id
+    try {
+      await expect(db.execute(`insert into sites (id, key, name, default_locale, production_origin)
+        values (gen_random_uuid(), '${key}', 'Dup', 'en', 'https://x.example')`)).rejects.toThrow()
+      await db.execute(`insert into site_config_revisions (id, site_id, version, data, checksum)
+        values (gen_random_uuid(), '${siteId}', 1, '{"a":1}', 'c1')`)
+      await expect(db.execute(`insert into site_config_revisions (id, site_id, version, data, checksum)
+        values (gen_random_uuid(), '${siteId}', 1, '{"a":2}', 'c2')`)).rejects.toThrow()
+    } finally {
+      await db.execute(`delete from site_config_revisions where site_id = '${siteId}'`)
+      await db.execute(`delete from sites where id = '${siteId}'`)
+    }
+  })
+})