feat: 迭代三大模块 + 全系统 Bug 修复

新功能：
- 账单筛选统计：多维度筛选面板 + 保存方案 + 结果统计
- 通知公告：系统公告/群组通知/个人提醒 + 通知中心页面
- 管理员后台：数据看板 + 用户管理 + 发布公告

Bug 修复：
- 统计页 fetchPrevMonthData/fetchMaxSingle 添加 group_id
- 群组视图添加 t.group_id 过滤，防止私人数据泄露
- 通知列表添加群组通知条件
- 通知标记已读添加错误处理
- 管理员 API 添加 affectedRows 检查
- 筛选面板金额为 0 时正确回填
- profile onShow 补充 userStore.fetchUserInfo
- 全系统样式修复（overflow/box-sizing）

server/src/db/init.ts

@@ -11,6 +11,14 @@ async function columnExists(conn: mysql.Connection, table: string, column: strin
   return (rows as any[])[0].cnt > 0
 }
 
+async function tableExists(conn: mysql.Connection, table: string): Promise<boolean> {
+  const [rows] = await conn.query(
+    `SELECT COUNT(*) as cnt FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = ?`,
+    [table]
+  )
+  return (rows as any[])[0].cnt > 0
+}
+
 async function runMigrations(conn: mysql.Connection) {
   console.log('[DB] Checking migrations...')
 
@@ -83,6 +91,49 @@ async function runMigrations(conn: mysql.Connection) {
     await conn.query("ALTER TABLE transactions ADD INDEX idx_group_date (group_id, date)")
     console.log('[DB] Groups migration complete')
   }
+
+  // users 表添加 role（管理员角色）
+  const hasRole = await columnExists(conn, 'users', 'role')
+  if (!hasRole) {
+    console.log('[DB] Migrating: adding role to users')
+    await conn.query("ALTER TABLE users ADD COLUMN role ENUM('user', 'admin') DEFAULT 'user' AFTER avatar_url")
+  }
+
+  // 通知表
+  const hasNotifications = await tableExists(conn, 'notifications')
+  if (!hasNotifications) {
+    console.log('[DB] Migrating: creating notifications table')
+    await conn.query(`
+      CREATE TABLE IF NOT EXISTS notifications (
+        id INT AUTO_INCREMENT PRIMARY KEY,
+        user_id INT DEFAULT NULL COMMENT 'NULL=系统公告，非NULL=个人通知',
+        group_id INT DEFAULT NULL COMMENT '群组通知关联',
+        type ENUM('system', 'group', 'personal') NOT NULL,
+        title VARCHAR(100) NOT NULL,
+        content TEXT,
+        is_read TINYINT(1) DEFAULT 0,
+        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        INDEX idx_user_read (user_id, is_read),
+        INDEX idx_type (type)
+      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+    `)
+  }
+
+  // 保存的筛选方案表
+  const hasSavedFilters = await tableExists(conn, 'saved_filters')
+  if (!hasSavedFilters) {
+    console.log('[DB] Migrating: creating saved_filters table')
+    await conn.query(`
+      CREATE TABLE IF NOT EXISTS saved_filters (
+        id INT AUTO_INCREMENT PRIMARY KEY,
+        user_id INT NOT NULL,
+        name VARCHAR(50) NOT NULL,
+        filters JSON NOT NULL COMMENT '筛选条件',
+        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
+    `)
+  }
 }
 
 export async function initDatabase() {

server/src/db/schema.sql

@@ -4,6 +4,7 @@ CREATE TABLE IF NOT EXISTS users (
   session_key VARCHAR(100),
   nickname VARCHAR(50) DEFAULT '小菜' COMMENT '用户昵称',
   avatar_url VARCHAR(500) DEFAULT '' COMMENT '头像URL',
+  role ENUM('user', 'admin') DEFAULT 'user' COMMENT '角色',
   created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
   updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
@@ -72,3 +73,25 @@ CREATE TABLE IF NOT EXISTS group_members (
   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;
+
+CREATE TABLE IF NOT EXISTS notifications (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  user_id INT DEFAULT NULL COMMENT 'NULL=系统公告，非NULL=个人通知',
+  group_id INT DEFAULT NULL COMMENT '群组通知关联',
+  type ENUM('system', 'group', 'personal') NOT NULL,
+  title VARCHAR(100) NOT NULL,
+  content TEXT,
+  is_read TINYINT(1) DEFAULT 0,
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  INDEX idx_user_read (user_id, is_read),
+  INDEX idx_type (type)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS saved_filters (
+  id INT AUTO_INCREMENT PRIMARY KEY,
+  user_id INT NOT NULL,
+  name VARCHAR(50) NOT NULL,
+  filters JSON NOT NULL COMMENT '筛选条件：{type, categories[], startDate, endDate, minAmount, maxAmount, keyword}',
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;