feat: 初始化 WWJ Cloud 企业级框架项目

- 后端：基于 NestJS 的分层架构设计
- 前端：基于 VbenAdmin + Element Plus 的管理系统
- 支持 SaaS + 独立版双架构模式
- 完整的用户权限管理系统
- 系统设置、文件上传、通知等核心功能
- 多租户支持和插件化扩展架构

wwjcloud/src/common/settings/email/email-settings.service.ts

@@ -0,0 +1,42 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { Injectable } from '@nestjs/common';
+import type { EmailSettingsVo } from './email-settings.dto';
+
+const SETTINGS_DIR = path.resolve(process.cwd(), 'config', 'runtime');
+const SETTINGS_FILE = path.resolve(SETTINGS_DIR, 'email.settings.json');
+
+const DEFAULT_SETTINGS: EmailSettingsVo = {
+  enabled: false,
+  host: '',
+  port: 465,
+  secure: true,
+  user: '',
+  pass: '',
+  from: '',
+};
+
+@Injectable()
+export class EmailSettingsService {
+  async getSettings(): Promise<EmailSettingsVo> {
+    try {
+      const buf = await fs.promises.readFile(SETTINGS_FILE, 'utf8');
+      const json = JSON.parse(buf);
+      return { ...DEFAULT_SETTINGS, ...json };
+    } catch {
+      return { ...DEFAULT_SETTINGS };
+    }
+  }
+
+  async updateSettings(patch: Partial<EmailSettingsVo>): Promise<EmailSettingsVo> {
+    const current = await this.getSettings();
+    const next: EmailSettingsVo = { ...current, ...patch };
+    await fs.promises.mkdir(SETTINGS_DIR, { recursive: true });
+    await fs.promises.writeFile(SETTINGS_FILE, JSON.stringify(next, null, 2), 'utf8');
+    return next;
+  }
+
+  static getSettingsPath() {
+    return SETTINGS_FILE;
+  }
+}