feat: 完整功能迭代 — 移动端+PC端全面优化

新增:
- 今日纪要 (6分类+彩色标签+时间选择器)
- 客户经理PC端工作台 (我的数据,5模块CRUD)
- 用户管理页 (支局长修改角色)
- 客户备注/收支费用(金额+单位)/联系人管理
- 拜访人姓名+电话字段
- 客户导入导出/旧周报导入模板下载
- 序号列+分页(25/50/100)

修复/优化:
- Hash路由→HTML5 History, Casdoor回调正常
- 时区统一为Asia/Shanghai (today_cst)
- 数据库懒加载→selectinload预加载
- 日期解析兼容ISO datetime字符串
- 文件上传定位修复 (position:relative)
- 表单button type='button'防止误提交
- 分管领导权限(只读客户档案,不可编辑)
- 侧边栏折叠+SVG图标
- 拜访方式/紧急度统一chip风格
- 时间范围统一为el-time-picker(is-range)
- 全局CSS设计变量+box-sizing修复滚动条

Co-Authored-By: Claude <noreply@anthropic.com>

backend/app/api/customers.py

@@ -93,9 +93,21 @@ async def list_customers(
     offset = (page - 1) * page_size
     query = base_query.order_by(Customer.name).offset(offset).limit(page_size)
     result = await db.execute(query)
+    items = result.scalars().all()
+
+    # Enrich with manager names
+    if items:
+        mgr_result = await db.execute(
+            select(CustomerAssignment.customer_id, User.name)
+            .join(User, CustomerAssignment.manager_id == User.id)
+            .where(CustomerAssignment.customer_id.in_([c.id for c in items]), CustomerAssignment.role == "primary")
+        )
+        mgr_map = {str(cid): name for cid, name in mgr_result.all()}
+        for item in items:
+            item.primary_manager_name = mgr_map.get(str(item.id), None)
 
     return CustomerListResponse(
-        items=result.scalars().all(),
+        items=items,
         total=total,
         page=page,
         page_size=page_size,
@@ -350,6 +362,8 @@ async def create_customer(
     current_user: dict = Depends(require_any_role),
     db: AsyncSession = Depends(get_db),
 ):
+    if current_user["role"] == "leader":
+        raise HTTPException(status_code=403, detail="分管领导无法创建客户")
     """Create a new customer with optional contacts and manager assignment."""
     import uuid
     customer = Customer(
@@ -390,6 +404,8 @@ async def update_customer(
     current_user: dict = Depends(require_any_role),
     db: AsyncSession = Depends(get_db),
 ):
+    if current_user["role"] == "leader":
+        raise HTTPException(status_code=403, detail="分管领导无法编辑客户")
     result = await db.execute(
         select(Customer).where(Customer.id == customer_id).options(selectinload(Customer.contacts))
     )