fix: add authorization header to AdminDashboardClient

Apply same EnsureAuthHeader pattern for consistency across all API
clients. Dashboard summary numbers now load correctly with proper JWT
authentication in Blazor Server environment.

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

TaxBaik.Web/Services/AdminDashboardClient.cs

@@ -1,3 +1,4 @@
+using System.Net.Http;
 using System.Net.Http.Json;
 using TaxBaik.Application.Services;
 using TaxBaik.Domain.Entities;
@@ -21,17 +22,28 @@ public class AdminDashboardClient : IAdminDashboardClient
 {
     private readonly HttpClient _http;
     private readonly ILogger<AdminDashboardClient> _logger;
+    private readonly ITokenStore _tokenStore;
 
-    public AdminDashboardClient(HttpClient http, ILogger<AdminDashboardClient> logger)
+    public AdminDashboardClient(HttpClient http, ILogger<AdminDashboardClient> logger, ITokenStore tokenStore)
     {
         _http = http;
         _logger = logger;
+        _tokenStore = tokenStore;
+    }
+
+    private void EnsureAuthHeader()
+    {
+        if (!string.IsNullOrEmpty(_tokenStore.AccessToken) && !_http.DefaultRequestHeaders.Contains("Authorization"))
+        {
+            _http.DefaultRequestHeaders.Authorization = new("Bearer", _tokenStore.AccessToken);
+        }
     }
 
     public async Task<AdminDashboardSummary> GetSummaryAsync(CancellationToken ct = default)
     {
         try
         {
+            EnsureAuthHeader();
             var result = await _http.GetFromJsonAsync<AdminDashboardSummary>(
                 "admin-dashboard/summary", cancellationToken: ct);
             return result ?? new(0, 0, 0, 0, []);
@@ -47,6 +59,7 @@ public class AdminDashboardClient : IAdminDashboardClient
     {
         try
         {
+            EnsureAuthHeader();
             var result = await _http.GetFromJsonAsync<ApiResponse<TaxFiling>>(
                 $"admin-dashboard/upcoming-filings?days={days}", cancellationToken: ct);
             return result?.Data ?? [];
@@ -62,6 +75,7 @@ public class AdminDashboardClient : IAdminDashboardClient
     {
         try
         {
+            EnsureAuthHeader();
             var result = await _http.GetFromJsonAsync<ApiResponse<Inquiry>>(
                 $"admin-dashboard/recent-inquiries?limit={limit}", cancellationToken: ct);
             return result?.Data ?? [];
@@ -77,6 +91,7 @@ public class AdminDashboardClient : IAdminDashboardClient
     {
         try
         {
+            EnsureAuthHeader();
             var url = "admin-dashboard/monthly-stats";
             if (!string.IsNullOrEmpty(month))
                 url += $"?month={month}";