fix: 统一用户有效期日期选择控件

ai_knowledge_base_v2/apps/admin-web/src/App.vue

@@ -285,13 +285,17 @@ async function createStudent() {
     nickname: studentForm.nickname || null,
     status: studentForm.status,
     dailyChatLimit: studentForm.dailyChatLimit,
-    expiredAt: studentForm.expiredAt || null,
+    expiredAt: toExpiryDateTime(studentForm.expiredAt),
   });
   ElMessage.success("学员已添加");
   resetStudentForm();
   await loadCurrentMenu();
 }
 
+function toExpiryDateTime(date: string) {
+  return date ? `${date}T23:59:59` : null;
+}
+
 function handleStudentImportFile(event: Event) {
   const input = event.target as HTMLInputElement;
   studentImportFile.value = input.files?.[0] ?? null;
@@ -840,12 +844,10 @@ function formatRecordDateTime(value: string, boundary: "start" | "end") {
                 <el-input v-model="studentForm.name" placeholder="姓名" />
                 <el-input v-model="studentForm.nickname" placeholder="昵称（可选）" />
                 <el-input-number v-model="studentForm.dailyChatLimit" :min="0" />
-                <el-date-picker
-                  v-model="studentForm.expiredAt"
-                  type="datetime"
-                  value-format="YYYY-MM-DDTHH:mm:ss"
-                  placeholder="有效期（可选）"
-                />
+                <label class="record-date-field student-expiry-field">
+                  <span>有效期</span>
+                  <input v-model="studentForm.expiredAt" type="date" aria-label="学员有效期" title="留空表示长期有效" />
+                </label>
                 <div class="form-switch-row">
                   <span>启用</span>
                   <el-switch v-model="studentForm.status" :active-value="1" :inactive-value="0" />

ai_knowledge_base_v2/apps/admin-web/src/styles.css

@@ -341,8 +341,11 @@ textarea {
 }
 
 .student-form-grid .el-input,
-.student-form-grid .el-input-number,
-.student-form-grid .el-date-editor {
+.student-form-grid .el-input-number {
+  width: 100%;
+}
+
+.student-expiry-field {
   width: 100%;
 }