feat: JWT 토큰 기반 Admin 로그인 인증 완성

- AuthService로 JWT 토큰 생성 및 검증
- CustomAuthenticationStateProvider를 통한 Blazor 인증 통합
- LocalStorageService로 토큰 관리
- Login.razor 완전 재작성 (실제 DB 검증, 토큰 발급)
- BCrypt 기반 비밀번호 검증
- admin/admin123으로 테스트 가능

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

TaxBaik.Admin/Components/Pages/Login.razor

@@ -1,9 +1,10 @@
 @page "/login"
 @using System.ComponentModel.DataAnnotations
-@using Microsoft.AspNetCore.Authentication
-@using Microsoft.AspNetCore.Authentication.Cookies
 @layout TaxBaik.Admin.Components.Layout.BlankLayout
 @attribute [AllowAnonymous]
+@inject AuthService AuthService
+@inject NavigationManager NavigationManager
+@inject CustomAuthenticationStateProvider AuthStateProvider
 
 <PageTitle>로그인</PageTitle>
 
@@ -24,7 +25,17 @@
             }
 
             <MudButton Variant="Variant.Filled" Color="Color.Primary" FullWidth="true"
-                Size="Size.Large" OnClick="HandleLogin">로그인</MudButton>
+                Size="Size.Large" OnClick="HandleLogin" Disabled="isLoading">
+                @if (isLoading)
+                {
+                    <MudProgressCircular Size="Size.Small" Indeterminate="true" Class="mr-2" />
+                    <span>로그인 중...</span>
+                }
+                else
+                {
+                    <span>로그인</span>
+                }
+            </MudButton>
         </MudForm>
     </MudPaper>
 </MudContainer>
@@ -32,30 +43,43 @@
 @code {
     private MudForm form;
     private bool isFormValid = false;
+    private bool isLoading = false;
     private string errorMessage = "";
 
     private LoginModel model = new();
 
     private async Task HandleLogin()
     {
-        // 기본 사용자명: admin / 비밀번호: admin123
-        if (model.Username == "admin" && model.Password == "admin123")
+        if (isLoading)
+            return;
+
+        isLoading = true;
+        errorMessage = "";
+
+        try
         {
-            // 임시: 대시보드로 리다이렉트 (향후 실제 쿠키 인증으로 개선)
-            NavigationManager.NavigateTo("/taxbaik/admin/dashboard", forceLoad: true);
+            var token = await AuthService.AuthenticateAndGenerateTokenAsync(model.Username, model.Password);
+
+            if (token == null)
+            {
+                errorMessage = "사용자명 또는 비밀번호가 올바르지 않습니다.";
+                isLoading = false;
+                return;
+            }
+
+            await AuthStateProvider.LoginAsync(token);
+            NavigationManager.NavigateTo("/taxbaik/admin/dashboard", forceLoad: false);
         }
-        else
+        catch (Exception ex)
         {
-            errorMessage = "사용자명 또는 비밀번호가 올바르지 않습니다.";
+            errorMessage = "로그인 중 오류가 발생했습니다.";
+            isLoading = false;
         }
     }
 
-    [Inject]
-    private NavigationManager NavigationManager { get; set; }
-
     private class LoginModel
     {
-        public string Username { get; set; }
-        public string Password { get; set; }
+        public string Username { get; set; } = "";
+        public string Password { get; set; } = "";
     }
 }

TaxBaik.Admin/Components/Routes.razor

@@ -1,14 +1,17 @@
 @using Microsoft.AspNetCore.Components.Routing
+@using Microsoft.AspNetCore.Components.Authorization
 
-<Router AppAssembly="typeof(Program).Assembly">
-    <Found Context="routeData">
-        <RouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />
-        <FocusOnNavigate RouteData="routeData" Selector="h1" />
-    </Found>
-    <NotFound>
-        <PageTitle>찾을 수 없음</PageTitle>
-        <LayoutView Layout="typeof(MainLayout)">
-            <p>요청한 페이지를 찾을 수 없습니다.</p>
-        </LayoutView>
-    </NotFound>
-</Router>
+<CascadingAuthenticationState>
+    <Router AppAssembly="typeof(Program).Assembly">
+        <Found Context="routeData">
+            <AuthorizeRouteView RouteData="routeData" DefaultLayout="typeof(MainLayout)" />
+            <FocusOnNavigate RouteData="routeData" Selector="h1" />
+        </Found>
+        <NotFound>
+            <PageTitle>찾을 수 없음</PageTitle>
+            <LayoutView Layout="typeof(MainLayout)">
+                <p>요청한 페이지를 찾을 수 없습니다.</p>
+            </LayoutView>
+        </NotFound>
+    </Router>
+</CascadingAuthenticationState>

TaxBaik.Admin/Components/_Imports.razor

@@ -7,3 +7,5 @@
 @using Microsoft.AspNetCore.Components.Authorization
 @using Microsoft.AspNetCore.Authorization
 @using MudBlazor
+@using TaxBaik.Admin.Services
+@attribute [Authorize]