fix: 新建表单客户选择器 — 提高 page_size 上限

- 前端三个页面: page_size 100 → 500（覆盖所有客户）
- 后端 customers API: page_size 上限 100 → 1000，默认 25 → 100

支局长/分管领导新建时下拉框可加载全量客户。

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

backend/app/api/customers.py

@@ -44,7 +44,7 @@ async def list_customers(
     service: Optional[str] = Query(None),
     manager_id: Optional[str] = Query(None),
     page: int = Query(1, ge=1),
-    page_size: int = Query(25, ge=1, le=100),
+    page_size: int = Query(100, ge=1, le=1000),
     current_user: dict = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):

frontend/src/views/desktop/KeyVisits.vue

@@ -48,7 +48,7 @@ async function loadUsers() {
 
 async function loadCustomers(q?: string) {
   try {
-    const params: any = { page_size: 100 }
+    const params: any = { page_size: 500 }
     if (q) params.search = q
     const res = await api.get('/customers/', { params })
     customers.value = res.data.items || []

frontend/src/views/desktop/MiniBusiness.vue

@@ -39,7 +39,7 @@ onMounted(async () => {
 
 async function loadCustomers(q?: string) {
   try {
-    const params: any = { page_size: 100 }
+    const params: any = { page_size: 500 }
     if (q) params.search = q
     const res = await api.get('/customers/', { params })
     customers.value = res.data.items || []

frontend/src/views/desktop/WorkPlans.vue

@@ -39,7 +39,7 @@ onMounted(async () => {
 
 async function loadCustomers(q?: string) {
   try {
-    const params: any = { page_size: 100 }
+    const params: any = { page_size: 500 }
     if (q) params.search = q
     const res = await api.get('/customers/', { params })
     customers.value = res.data.items || []