feat: 用户信息完善 + 一起记功能

- users 表添加 nickname、avatar_url 字段
- 用户信息 API（GET/PUT /me）+ 头像上传（multer）
- 头像通过 API 路由获取（公开，不经过 auth）
- 登录接口返回用户昵称和头像
- 用户信息 Store + 个人资料编辑页面
- 我的页面和首页显示真实用户信息
- 群组表（groups、group_members）+ transactions 添加 group_id
- 群组 API（创建/加入/退出/解散）
- 交易和统计 API 支持 group_id 视图切换
- 群组客户端 Store + 身份切换
- 群组管理页面
- App 初始化群组 Store
- UPLOAD_DIR 配置化
- Node.js 备份替代 mysqldump
- 统一前端 BASE_URL（config.ts）
- uploads 加入 .gitignore
- 修复 trust proxy 警告

server/src/db/init.ts

@@ -34,6 +34,55 @@ async function runMigrations(conn: mysql.Connection) {
     await conn.query('ALTER TABLE budgets ADD UNIQUE KEY uk_user_month (user_id, month)')
     console.log('[DB] budgets.user_id added')
   }
+
+  // users 表添加 nickname 和 avatar_url
+  const hasNickname = await columnExists(conn, 'users', 'nickname')
+  if (!hasNickname) {
+    console.log('[DB] Migrating: adding nickname to users')
+    await conn.query("ALTER TABLE users ADD COLUMN nickname VARCHAR(50) DEFAULT '小菜' COMMENT '用户昵称'")
+  }
+  const hasAvatarUrl = await columnExists(conn, 'users', 'avatar_url')
+  if (!hasAvatarUrl) {
+    console.log('[DB] Migrating: adding avatar_url to users')
+    await conn.query("ALTER TABLE users ADD COLUMN avatar_url VARCHAR(500) DEFAULT '' COMMENT '头像URL'")
+  }
+
+  // 群组表 + transactions.group_id
+  const hasGroupId = await columnExists(conn, 'transactions', 'group_id')
+  console.log(`[DB] transactions.group_id exists: ${hasGroupId}`)
+  if (!hasGroupId) {
+    console.log('[DB] Migrating: creating groups tables and adding group_id')
+
+    await conn.query(`
+      CREATE TABLE IF NOT EXISTS \`groups\` (
+        id INT AUTO_INCREMENT PRIMARY KEY,
+        name VARCHAR(100) NOT NULL,
+        invite_code VARCHAR(10) UNIQUE NOT NULL,
+        created_by INT NOT NULL,
+        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+        FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE CASCADE
+      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+    `)
+
+    await conn.query(`
+      CREATE TABLE IF NOT EXISTS group_members (
+        id INT AUTO_INCREMENT PRIMARY KEY,
+        group_id INT NOT NULL,
+        user_id INT NOT NULL,
+        role ENUM('owner', 'member') DEFAULT 'member',
+        nickname VARCHAR(50) DEFAULT '',
+        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        UNIQUE KEY uk_group_user (group_id, user_id),
+        FOREIGN KEY (group_id) REFERENCES \`groups\`(id) ON DELETE CASCADE,
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+    `)
+
+    await conn.query("ALTER TABLE transactions ADD COLUMN group_id INT DEFAULT NULL COMMENT '群组标签'")
+    await conn.query("ALTER TABLE transactions ADD INDEX idx_group_date (group_id, date)")
+    console.log('[DB] Groups migration complete')
+  }
 }
 
 export async function initDatabase() {