feat(api): argon2 password, idempotent admin seed, api-exception infra

Task 12 + Task 7 quality-review carryovers:

Part A - password hashing & controlled initial admin:
- src/auth/password.ts: hashPassword/verifyPassword over @node-rs/argon2
  (napi prebuilt, argon2id default); empty plain rejected at the door
- src/scripts/seed-admin.ts: idempotent admin seed (ADMIN_ACCOUNT/
  ADMIN_PASSWORD env, walk-up root .env load); existing account -> skip,
  never overwrites the password; no audit_logs (system op, no actor)
- pnpm seed script (build + node dist/scripts/seed-admin.js);
  .env.example dev defaults admin/admin-secret-change-me
- tests: test/password.spec.ts (5), test/seed.spec.ts real-DB idempotency (4)

Part B - Task 7 carryovers (all 8):
- ApiException(apiCode, message, httpStatus, details?) recognized first by
  the filter; unmapped-status rule: >=500 -> INTERNAL_ERROR + generic
  message, <500 -> VALIDATION_FAILED keeping original status (warn-logged)
- 5xx/INTERNAL_ERROR responses forced to generic message (leak fix)
- pino redact adds req.headers.cookie / res.headers.set-cookie
- x-request-id echo capped at 128 chars (fresh UUID beyond, no log)
- LOG_LEVEL validated against pino levels at module wiring -> fail fast
- shared/ constants (API_PREFIX), request-with-id, log-level (+spec)
- jest ts-jest reuses tsconfig.json; unit testMatch includes test/*.spec.ts
- build:watch script (no concurrently dep; dev = build:watch + node --watch)

api: 35 unit + 10 e2e tests green; root lint/typecheck/test green.

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

services/api/src/shared/request-with-id.ts

@@ -0,0 +1,14 @@
+// services/api/src/shared/request-with-id.ts —— 请求对象带 req.id 的共享类型
+// （Task 7 遗留项⑥）：request-id 中间件 / pino-http genReqId 写入，异常过滤器、
+// 后续 auth guard（req.user）等读取。此前在过滤器与中间件各声明一份局部接口。
+// 注意不继承 IncomingMessage：pino-http 经 module augmentation 给后者挂了
+// 非可选的 id: ReqId，扩展会与其冲突；组合用 ServerRequestWithId。
+import type { IncomingMessage } from 'node:http';
+
+/** 请求 ID 字段约定：上游 x-request-id 透传或 UUID v4（见 request-id.middleware.ts）。 */
+export interface RequestWithId {
+  id?: string;
+}
+
+/** 中间件/genReqId 实际操作的请求对象（node 原始请求 + id 字段）。 */
+export type ServerRequestWithId = IncomingMessage & RequestWithId;