feat(nestjs): support @ApiBearerAuth and custom auth decorators

[hyeonss0417]

Summary

Closes #94

This PR adds support for @ApiBearerAuth and per-operation security in NestJS mode.

Changes

Security Decorators Support

• @ApiBearerAuth(name?) - Bearer token authentication
• @ApiBasicAuth(name?) - Basic authentication
• @ApiOAuth2(scopes[], name?) - OAuth2 with scopes
• @ApiSecurity(name, scopes?) - Custom security scheme

Custom Auth Decorators via Config

Added authDecorators config option to support composite decorators:

{
  "nestjs": true,
  "openapi": {
    "securityDefinitions": {
      "bearerAuth": { "type": "http", "scheme": "bearer" }
    },
    "authDecorators": {
      "Auth": "bearerAuth",
      "AdminAuth": "bearerAuth"
    }
  }
}

Usage Example

@Controller('users')
export class UserController {
  @Get('me')
  @ApiBearerAuth('bearerAuth')  // ✅ Now recognized
  async getCurrentUser(): Promise<User> { }

  @Get('protected')
  @Auth()  // ✅ Custom decorator recognized via authDecorators config
  async getProtectedData(): Promise<Data> { }
}

Generated OpenAPI

paths:
  /users/me:
    get:
      security:
        - bearerAuth: []

Files Changed

• packages/tspec/src/types/tspec.ts - Added authDecorators option type
• packages/tspec/src/nestjs/types.ts - Added security field to method metadata
• packages/tspec/src/nestjs/parser.ts - Added security decorator parsing logic
• packages/tspec/src/nestjs/openapiGenerator.ts - Added security field to operations
• packages/tspec/src/generator/index.ts - Pass authDecorators to parser
• docs/guide/nestjs-integration.md - Added Security Decorators documentation

Tests

• ✅ All 134 tests passing
• Added tests for @ApiBearerAuth, @ApiBasicAuth, @ApiOAuth2, @ApiSecurity
• Added tests for custom auth decorators via authDecorators config

[github-actions]

LGTM 👍