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/customers.py

@@ -194,11 +194,11 @@ async def import_customers(
         raise HTTPException(status_code=400, detail=f"Excel 解析失败: {str(e)}")
 
     ws = wb.active
-    created, skipped = 0, 0
-    errors = []
+    created, updated, skipped = 0, 0, 0
+    reasons = []
 
-    # Build user name → id lookup
-    user_rows = await db.execute(select(User.name, User.id).where(User.role == "manager"))
+    # Build user name → id lookup (all users, not just managers)
+    user_rows = await db.execute(select(User.name, User.id))
     user_map = {name: uid for name, uid in user_rows.all()}
     default_user_id = uuid_mod.UUID(current_user["user_id"])
 
@@ -220,37 +220,45 @@ async def import_customers(
         contact_phone = str(row[9]).strip() if len(row) > 9 and row[9] else ""
         contact_role = str(row[10]).strip() if len(row) > 10 and row[10] else ""
 
-        existing = await db.execute(select(Customer).where(Customer.name == name))
-        if existing.scalar_one_or_none():
-            skipped += 1
-            continue
-
-        # Resolve manager: by name from template, or fallback to current user
         assignee_id = user_map.get(mgr_name, default_user_id)
 
+        existing_result = await db.execute(select(Customer).where(Customer.name == name))
+        existing = existing_result.scalar_one_or_none()
+
         try:
-            customer = Customer(
-                name=name, industry=industry, address=address,
-                in_use_services=services, monthly_fee=fee,
-                remarks=remarks,
-                created_by=default_user_id,
-            )
-            db.add(customer)
-            await db.flush()
-
-            if contact_name:
-                db.add(CustomerContact(customer_id=customer.id, name=contact_name, phone=contact_phone, role_desc=contact_role))
-
-            db.add(CustomerAssignment(
-                customer_id=customer.id, manager_id=assignee_id,
-                role="primary", assigned_by=default_user_id,
-            ))
-            created += 1
+            if existing:
+                # Update existing customer
+                existing.industry = industry or existing.industry
+                existing.address = address or existing.address
+                existing.in_use_services = services or existing.in_use_services
+                existing.monthly_fee = fee or existing.monthly_fee
+                existing.remarks = remarks or existing.remarks
+                # Update or create primary assignment if manager changed
+                if mgr_name:
+                    assign_rows = await db.execute(
+                        select(CustomerAssignment).where(CustomerAssignment.customer_id == existing.id, CustomerAssignment.role == "primary")
+                    )
+                    first_assign = assign_rows.first()
+                    if first_assign:
+                        first_assign[0].manager_id = assignee_id
+                    else:
+                        db.add(CustomerAssignment(customer_id=existing.id, manager_id=assignee_id, role="primary", assigned_by=default_user_id))
+                updated += 1
+                reasons.append(f"更新「{name}」的信息")
+            else:
+                customer = Customer(name=name, industry=industry, address=address, in_use_services=services, monthly_fee=fee, remarks=remarks, created_by=default_user_id)
+                db.add(customer)
+                await db.flush()
+                if contact_name:
+                    db.add(CustomerContact(customer_id=customer.id, name=contact_name, phone=contact_phone, role_desc=contact_role))
+                db.add(CustomerAssignment(customer_id=customer.id, manager_id=assignee_id, role="primary", assigned_by=default_user_id))
+                created += 1
+                reasons.append(f"新建「{name}」")
         except Exception as e:
-            errors.append(f"第{row_idx}行: {str(e)}")
+            errors.append(f"第{row_idx}行({name}): {str(e)}")
 
     await db.commit()
-    return {"created": created, "skipped": skipped, "errors": errors}
+    return {"created": created, "updated": updated, "skipped": skipped, "reasons": reasons, "errors": errors}
 
 
 @router.get("/check-duplicate/{name}")