refactor: 主动审计修复多处可观测性、依赖、代码质量缺口

通过并行 explore + librarian + 自查发现并修复：

代码缺陷
- shutdown.ts: db.$client.end().finally(...) 静默吞错——关闭失败会
  谎报 "DB pool closed" 后照常 exit 0。改用 await + try/catch
  分别记录成功/失败，setTimeout 也换成 Bun.sleep。
- interceptors.ts: 两条 instanceof ORPCError && instanceof
  ValidationError 重复检查，改用 early return + 单 if 分支区分 code。
- types.ts: 移除从未被引用的 RouterInputs 死代码（仅 RouterOutputs
  被 TodoItem 用到）。

Bun 原生 API（删/换 Node 兼容层）
- fields.ts: uuid v7 → Bun.randomUUIDv7()，删除 uuid 依赖
- migrate.ts: node:crypto.createHash → Bun.CryptoHasher.hash，
  少一个 Promise.all 项 + 一个 import
- shutdown.ts: setTimeout → Bun.sleep（顺带）

Biome 2.4 规则补强
- domains.types: "all"——开启类型感知规则集（noFloatingPromises /
  noMisusedPromises / useAwaitThenable / noUnnecessaryConditions
  等 Promise/异步陷阱）
- domains.drizzle: "recommended"、domains.react: "recommended"
- 显式开启 suspicious.noImportCycles（2.4 已 promote）

文档
- AGENTS.md 在 Stack & runtime 段加 "Prefer Bun-native APIs"
  原则，列出 UUIDv7/SHA-256/sleep/Bun.file 的优先路径
- AGENTS.md 在 Code style (Biome) 段记录本次启用的 lint domain
  与 noImportCycles 规则

验证：fix / typecheck / test 3/3 / build 568ms / compile 117M /
docker compose 全套（migrate JSON 日志 ✓、UUIDv7 写入 ✓、SIGTERM
shutdown 正确序列化 ✓）

bun.lock

@@ -25,7 +25,6 @@
         "postgres": "^3.4.9",
         "react": "^19.2.5",
         "react-dom": "^19.2.5",
-        "uuid": "^14.0.0",
         "zod": "^4.3.6",
       },
       "devDependencies": {
@@ -666,8 +665,6 @@
 
     "use-sync-external-store": ["use-sync-external-store@1.6.0", "", { "peerDependencies": { "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0" } }, "sha512-Pp6GSwGP/NrPIrxVFAIkOQeyw8lFenOHijQWkUTrDvrF4ALqylP2C/KCkeS9dpUM3KvYRQhna5vt7IL95+ZQ9w=="],
 
-    "uuid": ["uuid@14.0.0", "", { "bin": { "uuid": "dist-node/bin/uuid" } }, "sha512-Qo+uWgilfSmAhXCMav1uYFynlQO7fMFiMVZsQqZRMIXp0O7rR7qjkj+cPvBHLgBqi960QCoo/PH2/6ZtVqKvrg=="],
-
     "vite": ["vite@8.0.10", "", { "dependencies": { "lightningcss": "^1.32.0", "picomatch": "^4.0.4", "postcss": "^8.5.10", "rolldown": "1.0.0-rc.17", "tinyglobby": "^0.2.16" }, "optionalDependencies": { "fsevents": "~2.3.3" }, "peerDependencies": { "@types/node": "^20.19.0 || >=22.12.0", "@vitejs/devtools": "^0.1.0", "esbuild": "^0.27.0 || ^0.28.0", "jiti": ">=1.21.0", "less": "^4.0.0", "sass": "^1.70.0", "sass-embedded": "^1.70.0", "stylus": ">=0.54.8", "sugarss": "^5.0.0", "terser": "^5.16.0", "tsx": "^4.8.1", "yaml": "^2.4.2" }, "optionalPeers": ["@types/node", "@vitejs/devtools", "esbuild", "jiti", "less", "sass", "sass-embedded", "stylus", "sugarss", "terser", "tsx", "yaml"], "bin": { "vite": "bin/vite.js" } }, "sha512-rZuUu9j6J5uotLDs+cAA4O5H4K1SfPliUlQwqa6YEwSrWDZzP4rhm00oJR5snMewjxF5V/K3D4kctsUTsIU9Mw=="],
 
     "vitefu": ["vitefu@1.1.3", "", { "peerDependencies": { "vite": "^3.0.0 || ^4.0.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0" }, "optionalPeers": ["vite"] }, "sha512-ub4okH7Z5KLjb6hDyjqrGXqWtWvoYdU3IGm/NorpgHncKoLTCfRIbvlhBm7r0YstIaQRYlp4yEbFqDcKSzXSSg=="],