feat(init): 添加完整的认证和业务路由模块

- 实现微信登录、手机号绑定、token验证和登出功能
- 添加打卡系统，支持正常、迟到、请假等状态记录
- 集成课程投票功能，支持多课程选择和评分评论
- 开发反馈系统，支持图文反馈提交和管理员处理
- 构建首页页面模块，动态展示学习资源和个人信息
- 设计计划管理系统，支持周/月/年计划制定和跟踪
- 实现小组计划统计和历史记录查询功能
- 完善用户认证会话管理和数据库交互逻辑

user.py

@@ -0,0 +1,47 @@
+import re
+
+from . import db
+
+
+def make_display_name(group, name):
+    if group and re.match(r"^\d{2}组$", group):
+        return group + name
+    return name
+
+
+def get_class_groups(user_id):
+    return db.fetch_all(
+        "SELECT c.id AS class_id, c.code AS class_code, c.name AS period, "
+        "g.group_code AS `group`, cg.role_in_group AS role "
+        "FROM class_groups cg "
+        "JOIN classes c ON c.id=cg.class_id "
+        "JOIN `groups` g ON g.id=cg.group_id "
+        "WHERE cg.user_id=%s ORDER BY c.id, g.sort",
+        (user_id,),
+    )
+
+
+def get_history_groups(user_id):
+    return db.fetch_all(
+        "SELECT og.group_code AS old_group FROM group_history gh "
+        "JOIN classes c ON c.id=gh.class_id "
+        "LEFT JOIN `groups` og ON og.id=gh.old_group_id "
+        "WHERE gh.user_id=%s ORDER BY gh.changed_at DESC",
+        (user_id,),
+    )
+
+
+def user_payload(user):
+    group = user.get("group") or ""
+    class_groups = get_class_groups(user["id"])
+    history_groups = [h["old_group"] for h in get_history_groups(user["id"])]
+    return {
+        "name": user["name"],
+        "student_id": user["student_id"],
+        "role": user.get("role", "student"),
+        "group": group,
+        "display_name": make_display_name(group, user["name"]),
+        "class_groups": class_groups,
+        "history_groups": history_groups,
+        "first_login": bool(user.get("first_login")),
+    }