feat: 支局长/分管领导可为任意客户经理代填记录

后端:
- 5个模块的 Create/Update schema 新增可选 manager_id 字段
- POST 端点: director/leader 可指定 manager_id，manager 角色自动用自身
- PUT 端点: director/leader 可修改 manager_id，manager 角色禁止修改

前端（移动端+桌面端共10个页面）:
- 支局长/领导可见「客户经理」下拉选择框
- 创建和编辑时均可指定记录归属的客户经理
- 涵盖今日拜访、今日纪要、工作计划、商机跟单、要客拜访五个模块

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

frontend/src/views/desktop/WorkPlans.vue

@@ -14,6 +14,7 @@ const themeStore = useThemeStore()
 const loading = ref(false)
 const workPlans = ref<any[]>([])
 const customers = ref<any[]>([])
+const allManagers = ref<any[]>([])
 const shotRef = ref<HTMLElement | null>(null)
 const { capturing, captureEl } = useScreenshot()
 
@@ -65,6 +66,9 @@ const managerSummary = computed(() => {
 
 onMounted(async () => {
   await Promise.all([loadPlans(), loadCustomers(), loadManagerColors()])
+  if (auth.isDirector || auth.isLeader) {
+    api.get('/users/', { params: { role: 'manager' } }).then(r => { allManagers.value = r.data }).catch(() => {})
+  }
 })
 
 const customerSearch = ref('')
@@ -111,7 +115,7 @@ async function loadPlans() {
 
 function openCreate() {
   dialogMode.value = 'create'
-  form.value = { customer_id: '', plan_content: '', plan_date: todayStr(), status: '计划中' }
+  form.value = { customer_id: '', plan_content: '', plan_date: todayStr(), status: '计划中', manager_id: auth.userId || '' }
   dialogVisible.value = true
 }
 
@@ -270,6 +274,11 @@ async function quickStatusChange(row: any, newStatus: string) {
             </template>
           </el-select>
         </el-form-item>
+        <el-form-item v-if="auth.isDirector || auth.isLeader" label="客户经理">
+          <el-select v-model="form.manager_id" filterable placeholder="选择客户经理" style="width:100%">
+            <el-option v-for="m in allManagers" :key="m.id" :label="m.name" :value="m.id" />
+          </el-select>
+        </el-form-item>
         <el-form-item label="计划拜访时间">
           <el-date-picker v-model="form.plan_date" type="date" style="width:100%" />
         </el-form-item>