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。

apps/api/src/common/errors/app-exception.ts

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+import { ERROR_MESSAGES, type ErrorCode, httpStatusOf } from '@lingxi/shared';
+
+export interface AppExceptionOptions {
+  code: ErrorCode;
+  message?: string;
+  details?: unknown;
+}
+
+/**
+ * 业务异常：由统一异常过滤器序列化为 { code, message, details, trace_id }。
+ * 业务代码禁止直接 throw new Error 表达可预期错误。
+ */
+export class AppException extends Error {
+  readonly code: ErrorCode;
+  readonly status: number;
+  readonly details?: unknown;
+
+  constructor(options: AppExceptionOptions) {
+    super(options.message ?? ERROR_MESSAGES[options.code]);
+    this.name = 'AppException';
+    this.code = options.code;
+    this.status = httpStatusOf(options.code);
+    this.details = options.details;
+  }
+}

apps/api/src/common/filters/all-exceptions.filter.spec.ts

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+import { ErrorCode } from '@lingxi/shared';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { createTestApp, type TestApp } from '../../testing/test-app';
+
+describe('统一异常过滤器（冒烟）', () => {
+  let testApp: TestApp;
+
+  beforeAll(async () => {
+    testApp = await createTestApp({ includeErrorRoutes: true });
+  });
+
+  afterAll(async () => {
+    await testApp.app.close();
+  });
+
+  it('AppException 输出业务错误码与 trace_id', async () => {
+    const response = await testApp.app.inject({ method: 'GET', url: '/api/v1/__test/app-error' });
+    expect(response.statusCode).toBe(409);
+    const body = response.json<{ code: number; message: string; trace_id: string }>();
+    expect(body.code).toBe(ErrorCode.STATE_NOT_ALLOWED);
+    expect(body.message).toBe('当前状态不允许该操作');
+    expect(body.trace_id.length).toBeGreaterThan(0);
+  });
+
+  it('HttpException 404 映射为 40401', async () => {
+    const response = await testApp.app.inject({ method: 'GET', url: '/api/v1/__test/http-404' });
+    expect(response.statusCode).toBe(404);
+    expect(response.json<{ code: number }>().code).toBe(ErrorCode.NOT_FOUND);
+  });
+
+  it('未知异常收敛为 50001，不泄露内部信息', async () => {
+    const response = await testApp.app.inject({ method: 'GET', url: '/api/v1/__test/boom' });
+    expect(response.statusCode).toBe(500);
+    const body = response.json<{ code: number; message: string; trace_id: string }>();
+    expect(body.code).toBe(ErrorCode.INTERNAL_ERROR);
+    expect(body.message).toBe('服务内部错误');
+    expect(body.trace_id.length).toBeGreaterThan(0);
+  });
+
+  it('未注册路由返回统一 404 错误体', async () => {
+    const response = await testApp.app.inject({ method: 'GET', url: '/api/v1/not-exists' });
+    expect(response.statusCode).toBe(404);
+    expect(response.json<{ code: number }>().code).toBe(ErrorCode.NOT_FOUND);
+  });
+});

apps/api/src/common/filters/all-exceptions.filter.ts

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+import { type ApiErrorBody, ErrorCode, httpStatusOf, isErrorCode } from '@lingxi/shared';
+import { type ArgumentsHost, Catch, type ExceptionFilter, HttpException } from '@nestjs/common';
+
+import { AppException } from '../errors/app-exception';
+
+interface RequestWithTrace {
+  id?: string;
+  url?: string;
+  method?: string;
+  log?: {
+    error: (payload: unknown, message?: string) => void;
+  };
+}
+
+interface ReplyLike {
+  status: (code: number) => { send: (body: unknown) => void };
+}
+
+function codeFromHttpStatus(status: number): ErrorCode {
+  switch (status) {
+    case 400:
+      return ErrorCode.PARAM_INVALID;
+    case 401:
+      return ErrorCode.UNAUTHENTICATED;
+    case 403:
+      return ErrorCode.PERMISSION_DENIED;
+    case 404:
+      return ErrorCode.NOT_FOUND;
+    case 409:
+      return ErrorCode.STATE_NOT_ALLOWED;
+    case 422:
+      return ErrorCode.BUSINESS_RULE_VIOLATION;
+    case 429:
+      return ErrorCode.RATE_LIMITED;
+    case 502:
+    case 503:
+      return ErrorCode.DEPENDENCY_UNAVAILABLE;
+    case 504:
+      return ErrorCode.TIMEOUT;
+    default:
+      return status >= 400 && status < 500 ? ErrorCode.PARAM_INVALID : ErrorCode.INTERNAL_ERROR;
+  }
+}
+
+function messageFromHttpException(exception: HttpException): string {
+  const response = exception.getResponse();
+  if (typeof response === 'string') {
+    return response;
+  }
+  if ('message' in response) {
+    const message = response.message;
+    if (typeof message === 'string') {
+      return message;
+    }
+    if (Array.isArray(message) && message.length > 0 && typeof message[0] === 'string') {
+      return message.join('; ');
+    }
+  }
+  return exception.message;
+}
+
+/**
+ * 全局异常过滤器：所有错误统一输出 { code, message, details, trace_id }（工程规范 04）。
+ * trace_id 与 Pino 的 request id 同源，响应用户报障时可反查日志。
+ */
+@Catch()
+export class AllExceptionsFilter implements ExceptionFilter {
+  catch(exception: unknown, host: ArgumentsHost): void {
+    const context = host.switchToHttp();
+    const request = context.getRequest<RequestWithTrace>();
+    const reply = context.getResponse<ReplyLike>();
+    const traceId = request.id ?? '';
+
+    let status = 500;
+    let body: ApiErrorBody;
+
+    if (exception instanceof AppException) {
+      status = exception.status;
+      body = {
+        code: exception.code,
+        message: exception.message,
+        ...(exception.details === undefined ? {} : { details: exception.details }),
+        trace_id: traceId,
+      };
+    } else if (exception instanceof HttpException) {
+      status = exception.getStatus();
+      const code = codeFromHttpStatus(status);
+      body = {
+        code,
+        message: status >= 500 ? '服务内部错误' : messageFromHttpException(exception),
+        trace_id: traceId,
+      };
+    } else {
+      body = {
+        code: ErrorCode.INTERNAL_ERROR,
+        message: '服务内部错误',
+        trace_id: traceId,
+      };
+    }
+
+    if (status >= 500) {
+      request.log?.error(
+        {
+          err: exception,
+          trace_id: traceId,
+          method: request.method,
+          url: request.url,
+          code: body.code,
+        },
+        'request failed',
+      );
+    }
+
+    reply.status(status).send(body);
+  }
+}
+
+/** 供测试或未来的 OpenAPI 生成复用：确认错误码与 HTTP 状态一致 */
+export function httpStatusForCode(code: number): number {
+  return isErrorCode(code) ? httpStatusOf(code) : 500;
+}

apps/api/src/common/http/error-response.dto.ts

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+import { ApiProperty } from '@nestjs/swagger';
+
+/** OpenAPI 错误响应模型（工程规范 04 统一错误体） */
+export class ErrorResponseDto {
+  @ApiProperty({ type: Number, description: '错误码（见 ErrorCode 常量）', example: 42202 })
+  code!: number;
+
+  @ApiProperty({ type: String, description: '可直接展示给用户的提示', example: '内容触发合规拦截' })
+  message!: string;
+
+  @ApiProperty({
+    type: Object,
+    description: '补充信息（字段错误、命中规则等），结构由错误码决定',
+    required: false,
+    example: { issues: [{ path: 'name', message: 'Required' }] },
+  })
+  details?: unknown;
+
+  @ApiProperty({
+    type: String,
+    description: '请求追踪 ID，与日志同源',
+    example: '01JABCDEF0123456789ABCDEFG',
+  })
+  trace_id!: string;
+}

apps/api/src/common/pipes/zod-validation.pipe.spec.ts

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+import { ErrorCode } from '@lingxi/shared';
+import { describe, expect, it } from 'vitest';
+import { z } from 'zod';
+
+import { AppException } from '../errors/app-exception';
+import { ZodValidationPipe } from './zod-validation.pipe';
+
+const schema = z.object({
+  name: z.string().min(2),
+  limit: z.coerce.number().int().min(1).max(100).default(20),
+});
+
+describe('ZodValidationPipe', () => {
+  it('通过校验并返回转换后的值', () => {
+    const pipe = new ZodValidationPipe(schema);
+    expect(pipe.transform({ name: '素材', limit: '30' })).toEqual({ name: '素材', limit: 30 });
+  });
+
+  it('缺省值生效', () => {
+    const pipe = new ZodValidationPipe(schema);
+    expect(pipe.transform({ name: '素材' })).toEqual({ name: '素材', limit: 20 });
+  });
+
+  it('校验失败抛 40001，details 带字段错误', () => {
+    const pipe = new ZodValidationPipe(schema);
+    try {
+      pipe.transform({ name: 'x' });
+      throw new Error('应当抛错');
+    } catch (error) {
+      expect(error).toBeInstanceOf(AppException);
+      const appError = error instanceof AppException ? error : null;
+      expect(appError?.code).toBe(ErrorCode.PARAM_INVALID);
+      expect(appError?.status).toBe(400);
+      expect(appError?.details).toMatchObject({
+        issues: [{ path: 'name' }],
+      });
+    }
+  });
+});

apps/api/src/common/pipes/zod-validation.pipe.ts

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+import { ErrorCode } from '@lingxi/shared';
+import { type PipeTransform } from '@nestjs/common';
+import type { ZodSchema } from 'zod';
+
+import { AppException } from '../errors/app-exception';
+
+/**
+ * Zod 校验管道（静态 DTO）：body / query / params 共用。
+ * 校验失败统一转 40001，并把字段错误放进 details.issues，便于前端定位。
+ */
+export class ZodValidationPipe<T> implements PipeTransform<unknown, T> {
+  constructor(private readonly schema: ZodSchema<T>) {}
+
+  transform(value: unknown): T {
+    const result = this.schema.safeParse(value);
+    if (!result.success) {
+      throw new AppException({
+        code: ErrorCode.PARAM_INVALID,
+        message: '参数校验失败',
+        details: {
+          issues: result.error.issues.map((issue) => ({
+            path: issue.path.join('.'),
+            message: issue.message,
+          })),
+        },
+      });
+    }
+    return result.data;
+  }
+}