feat: 历史周报+图片预览+照片管理+导入优化+用户合并

新增:
- 历史周报: Dashboard/周报详情支持周选择器翻看往周，归档只读
- 图片预览: 全屏大图(移动端+PC端)，点击遮罩关闭
- PC端照片管理: 编辑时可上传/删除照片
- 客户导入改为更新模式: 重名自动更新信息，显示操作明细
- 导入跳过原因: 旧周报导入也显示每条跳过原因

优化:
- 填报进度权限: 经理只看到自己，支局长/领导看全员
- 客户经理暖灰色hash标签列
- 用户去重合并(4组)，数据完整迁移
- CLAUDE.md 更新到最新状态

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

backend/app/api/dashboard.py

@@ -1,4 +1,5 @@
 import uuid
+from datetime import date
 from typing import Optional
 from fastapi import APIRouter, Depends, Query
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -11,35 +12,42 @@ router = APIRouter(prefix="/dashboard", tags=["Dashboard"])
 
 @router.get("/stats")
 async def dashboard_stats(
+    reference_date: Optional[str] = Query(None),
     current_user: dict = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
-    """Get dashboard card statistics for the current week."""
-    stats = await get_dashboard_stats(db)
+    """Get dashboard card statistics. Pass reference_date (YYYY-MM-DD) for historical weeks."""
+    ref = date.fromisoformat(reference_date) if reference_date else None
+    stats = await get_dashboard_stats(db, ref)
     return stats
 
 
 @router.get("/progress")
 async def reporting_progress(
+    reference_date: Optional[str] = Query(None),
     current_user: dict = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
-    """Get per-manager reporting progress."""
-    return await get_reporting_progress(db)
+    """Get per-manager reporting progress. Managers only see themselves."""
+    ref = date.fromisoformat(reference_date) if reference_date else None
+    return await get_reporting_progress(db, ref, current_user["user_id"], current_user["role"])
 
 
 @router.get("/weekly-report")
 async def weekly_report(
     manager_id: Optional[str] = Query(None),
     customer_id: Optional[str] = Query(None),
+    reference_date: Optional[str] = Query(None),
     current_user: dict = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
-    """Get full weekly report data (four modules)."""
+    """Get full weekly report data. Pass reference_date for historical weeks."""
+    ref = date.fromisoformat(reference_date) if reference_date else None
     return await get_weekly_report(
         db=db,
         user_id=uuid.UUID(current_user["user_id"]),
         role=current_user["role"],
         filter_manager_id=uuid.UUID(manager_id) if manager_id else None,
         filter_customer_id=uuid.UUID(customer_id) if customer_id else None,
+        reference_date=ref,
     )