feat: add admin password change form

TaxBaik.Web/Components/Admin/Pages/Settings/SiteSettings.razor

@@ -1,5 +1,8 @@
 @page "/admin/settings"
+@using System.ComponentModel.DataAnnotations
+@using TaxBaik.Web.Services
 @using TaxBaik.Domain.Interfaces
+@inject IApiClient ApiClient
 @inject ISnackbar Snackbar
 
 <PageTitle>설정</PageTitle>
@@ -25,11 +28,36 @@
     </MudForm>
 </MudPaper>
 
+<MudPaper Class="pa-4 mt-4" Elevation="1">
+    <MudText Typo="Typo.h6" Class="mb-4">계정 관리</MudText>
+
+    <MudForm>
+        <MudTextField @bind-Value="currentPassword" Label="현재 비밀번호" InputType="InputType.Password"
+            Variant="Variant.Outlined" Class="mb-4" />
+
+        <MudTextField @bind-Value="newPassword" Label="새 비밀번호" InputType="InputType.Password"
+            Variant="Variant.Outlined" Class="mb-4" />
+
+        <MudTextField @bind-Value="confirmNewPassword" Label="새 비밀번호 확인" InputType="InputType.Password"
+            Variant="Variant.Outlined" Class="mb-4" />
+
+        <MudButton Variant="Variant.Filled" Color="Color.Primary"
+            Disabled="@isChangingPassword"
+            @onclick="ChangePassword">
+            @(isChangingPassword ? "변경 중..." : "비밀번호 변경")
+        </MudButton>
+    </MudForm>
+</MudPaper>
+
 @code {
     private string phone = "010-4122-8268";
     private string email = "taxbaik5668@gmail.com";
     private string kakaoUrl = "http://pf.kakao.com/_xoxchTX";
     private string instagramUrl = "https://www.instagram.com/taxtory5668/";
+    private string currentPassword = "";
+    private string newPassword = "";
+    private string confirmNewPassword = "";
+    private bool isChangingPassword;
 
     private async Task SaveSettings()
     {
@@ -37,4 +65,57 @@
         Snackbar.Add("설정 저장 기능은 아직 구현되지 않았습니다.", Severity.Info);
         await Task.CompletedTask;
     }
+
+    private async Task ChangePassword()
+    {
+        if (isChangingPassword)
+            return;
+
+        if (string.IsNullOrWhiteSpace(currentPassword) || string.IsNullOrWhiteSpace(newPassword))
+        {
+            Snackbar.Add("현재 비밀번호와 새 비밀번호를 입력하세요.", Severity.Warning);
+            return;
+        }
+
+        if (newPassword != confirmNewPassword)
+        {
+            Snackbar.Add("새 비밀번호 확인이 일치하지 않습니다.", Severity.Warning);
+            return;
+        }
+
+        isChangingPassword = true;
+
+        try
+        {
+            var response = await ApiClient.PostAsync<ChangePasswordResponse>("auth/change-password", new
+            {
+                CurrentPassword = currentPassword,
+                NewPassword = newPassword
+            });
+
+            if (response?.Message == null)
+            {
+                Snackbar.Add("비밀번호 변경에 실패했습니다.", Severity.Error);
+                return;
+            }
+
+            Snackbar.Add(response.Message, Severity.Success);
+            currentPassword = "";
+            newPassword = "";
+            confirmNewPassword = "";
+        }
+        catch
+        {
+            Snackbar.Add("비밀번호 변경 중 오류가 발생했습니다.", Severity.Error);
+        }
+        finally
+        {
+            isChangingPassword = false;
+        }
+    }
+
+    private class ChangePasswordResponse
+    {
+        public string Message { get; set; } = "";
+    }
 }