polish: refine admin ui controls

src/app/(admin)/admin/users/user-form.tsx

@@ -6,6 +6,13 @@ import { PendingSubmitButton } from "@/components/shared/pending-submit-button";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
 import {
   Dialog,
   DialogContent,
@@ -54,11 +61,11 @@ export function UserForm({
           <DialogTitle>{isEdit ? "编辑用户" : "创建用户"}</DialogTitle>
         </DialogHeader>
         <form action={handleSubmit} className="space-y-5">
-          <div>
+          <div className="space-y-2">
             <Label>邮箱</Label>
             <Input name="email" type="email" defaultValue={user?.email} required />
           </div>
-          <div>
+          <div className="space-y-2">
             <Label>{isEdit ? "新密码（可留空）" : "密码"}</Label>
             <Input
               name="password"
@@ -68,20 +75,24 @@ export function UserForm({
               placeholder={isEdit ? "留空则保持不变" : undefined}
             />
           </div>
-          <div>
+          <div className="space-y-2">
             <Label>昵称</Label>
             <Input name="name" defaultValue={user?.name ?? ""} />
           </div>
-          <div>
-            <Label>角色</Label>
-            <select
+          <div className="space-y-2">
+            <Label htmlFor="user-role">角色</Label>
+            <Select
               name="role"
               defaultValue={user?.role ?? "USER"}
-              className="h-10 w-full px-3 text-sm outline-none"
             >
-              <option value="USER">普通用户</option>
-              <option value="ADMIN">管理员</option>
-            </select>
+              <SelectTrigger id="user-role" className="w-full">
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent align="start">
+                <SelectItem value="USER">普通用户</SelectItem>
+                <SelectItem value="ADMIN">管理员</SelectItem>
+              </SelectContent>
+            </Select>
           </div>
           <PendingSubmitButton className="w-full" pendingLabel={isEdit ? "保存中..." : "创建中..."}>
             {isEdit ? "保存" : "创建"}