修复前后端显示异常问题（受试者、中心、负责人、日期等）

frontend/src/components/TaskForm.vue

@@ -13,7 +13,9 @@
         </el-select>
       </el-form-item>
       <el-form-item label="负责人" prop="assignee_id">
-        <UserSelect v-model="form.assignee_id" placeholder="选择负责人" />
+        <el-select v-model="form.assignee_id" placeholder="选择负责人" filterable clearable>
+          <el-option v-for="m in assigneeOptions" :key="m.value" :label="m.label" :value="m.value" />
+        </el-select>
       </el-form-item>
       <el-form-item label="优先级" prop="priority">
         <el-select v-model="form.priority" placeholder="请选择">
@@ -42,12 +44,12 @@ import type { FormInstance, FormRules } from "element-plus";
 import { ElMessage } from "element-plus";
 import { createTask, updateTask } from "../api/tasks";
 import { useStudyStore } from "../store/study";
-import UserSelect from "./selectors/UserSelect.vue";
 
 interface Props {
   modelValue: boolean;
   task?: Record<string, any>;
   milestones: any[];
+  members?: any[];
 }
 
 const props = defineProps<Props>();
@@ -89,6 +91,20 @@ const rules: FormRules = {
 
 const submitting = ref(false);
 const isEdit = computed(() => !!props.task);
+const assigneeOptions = computed(() => {
+  const seen = new Set<string>();
+  return (props.members || [])
+    .filter((m: any) => m.is_active !== false)
+    .map((m: any) => {
+      const user = m.user || {};
+      return { value: m.user_id, label: user.display_name || user.username || m.username || "—" };
+    })
+    .filter((opt) => {
+      if (seen.has(opt.value)) return false;
+      seen.add(opt.value);
+      return true;
+    });
+});
 
 watch(
   () => props.task,