fix(user-management): 修复用户管理测试 - 添加用户创建API和模态框等待逻辑

问题：
- 用户管理页面输入框缺少name属性
- API缺少POST方法处理用户创建
- 测试未等待模态框打开

修复：
1. 应用代码：为创建/编辑模态框的输入框添加name属性
2. API：添加POST方法处理用户创建请求
3. 测试：增加模态框等待逻辑和详细日志

测试结果：
- Chromium: ✓ 通过
- Firefox: ✓ 通过

src/app/admin/users/page.tsx

@@ -262,6 +262,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">邮箱</label>
                 <input
                   type="email"
+                  name="email"
                   value={formData.email}
                   onChange={(e) => setFormData({ ...formData, email: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -271,6 +272,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">姓名</label>
                 <input
                   type="text"
+                  name="name"
                   value={formData.name}
                   onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -280,6 +282,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">密码</label>
                 <input
                   type="password"
+                  name="password"
                   value={formData.password}
                   onChange={(e) => setFormData({ ...formData, password: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -288,6 +291,7 @@ export default function UsersPage() {
               <div>
                 <label className="block text-sm font-medium text-gray-700 mb-1">角色</label>
                 <select
+                  name="role"
                   value={formData.role}
                   onChange={(e) => setFormData({ ...formData, role: e.target.value as any })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -330,6 +334,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">邮箱</label>
                 <input
                   type="email"
+                  name="email"
                   value={formData.email}
                   onChange={(e) => setFormData({ ...formData, email: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -339,6 +344,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">姓名</label>
                 <input
                   type="text"
+                  name="name"
                   value={formData.name}
                   onChange={(e) => setFormData({ ...formData, name: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -348,6 +354,7 @@ export default function UsersPage() {
                 <label className="block text-sm font-medium text-gray-700 mb-1">新密码（留空则不修改）</label>
                 <input
                   type="password"
+                  name="password"
                   value={formData.password}
                   onChange={(e) => setFormData({ ...formData, password: e.target.value })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"
@@ -356,6 +363,7 @@ export default function UsersPage() {
               <div>
                 <label className="block text-sm font-medium text-gray-700 mb-1">角色</label>
                 <select
+                  name="role"
                   value={formData.role}
                   onChange={(e) => setFormData({ ...formData, role: e.target.value as any })}
                   className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-[#C41E3A]"