feat(api): 搭建 API 与 Worker 骨架及契约基线

NestJS 11 + Fastify 统一错误体与 trace_id，/health 真实探活 DB/Redis，OpenAPI 3.1 契约含 20 个错误码；shared 包提供错误码、权限点、ULID、分页与通用 schema；worker 完成队列进程骨架。

packages/shared/src/ulid.ts

@@ -0,0 +1,56 @@
+/**
+ * ULID 生成与解析（Crockford Base32，26 字符 = 48bit 时间 + 80bit 随机）
+ * 主键统一由应用侧生成 char(26) ULID（工程规范 05）。
+ */
+import { ULID_LENGTH } from './constants.js';
+
+const ENCODING = '0123456789ABCDEFGHJKMNPQRSTVWXYZ';
+const ENCODING_LEN = 32;
+
+export const ULID_PATTERN = /^[0-9A-HJKMNP-TV-Z]{26}$/;
+
+function randomBytes(length: number): Uint8Array {
+  const bytes = new Uint8Array(length);
+  globalThis.crypto.getRandomValues(bytes);
+  return bytes;
+}
+
+/** 生成 ULID；同一毫秒内依靠 80bit 随机数避免碰撞 */
+export function ulid(timestamp: number = Date.now()): string {
+  if (!Number.isInteger(timestamp) || timestamp < 0 || timestamp > 0xffffffffffff) {
+    throw new RangeError('ULID 时间戳必须是 48bit 非负整数');
+  }
+  let time = timestamp;
+  const timeChars: string[] = new Array<string>(10);
+  for (let i = 9; i >= 0; i -= 1) {
+    timeChars[i] = ENCODING[time % ENCODING_LEN] ?? '0';
+    time = Math.floor(time / ENCODING_LEN);
+  }
+  const randomChars = Array.from(randomBytes(16), (byte) => ENCODING[byte & 31] ?? '0');
+  return `${timeChars.join('')}${randomChars.join('')}`;
+}
+
+export function isUlid(value: string): boolean {
+  return value.length === ULID_LENGTH && ULID_PATTERN.test(value);
+}
+
+/** 解析 ULID 前 10 位得到毫秒时间戳 */
+export function ulidToTimestamp(id: string): number {
+  if (!isUlid(id)) {
+    throw new TypeError(`不是合法 ULID：${id}`);
+  }
+  let timestamp = 0;
+  for (let i = 0; i < 10; i += 1) {
+    const char = id[i] ?? '';
+    const value = ENCODING.indexOf(char);
+    if (value < 0) {
+      throw new TypeError(`ULID 含非法字符：${char}`);
+    }
+    timestamp = timestamp * ENCODING_LEN + value;
+  }
+  return timestamp;
+}
+
+export function ulidToDate(id: string): Date {
+  return new Date(ulidToTimestamp(id));
+}