Refactor admin dashboard and standardize UI shells

src/TaxBaik.Web/Endpoints/Admin/ValidationEndpoints.cs

@@ -18,7 +18,7 @@ public class ValidateSitemapEndpoint : EndpointWithoutRequest
     public override void Configure()
     {
         Get("/api/admin/validate/sitemap");
-        Roles("admin");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(CancellationToken ct)
@@ -40,7 +40,7 @@ public class ValidateRssEndpoint : EndpointWithoutRequest
     public override void Configure()
     {
         Get("/api/admin/validate/rss");
-        Roles("admin");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(CancellationToken ct)
@@ -62,7 +62,7 @@ public class ValidateConsistencyEndpoint : EndpointWithoutRequest
     public override void Configure()
     {
         Get("/api/admin/validate/consistency");
-        Roles("admin");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(CancellationToken ct)

src/TaxBaik.Web/Endpoints/AdminDashboard/GetMonthlyStatsEndpoint.cs

@@ -15,7 +15,7 @@ public class GetMonthlyStatsEndpoint : Endpoint<MonthlyStatsQuery, MonthlyStatsR
     public override void Configure()
     {
         Get("/api/admin-dashboard/monthly-stats");
-        Policies("Bearer");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(MonthlyStatsQuery request, CancellationToken ct)

src/TaxBaik.Web/Endpoints/AdminDashboard/GetRecentInquiriesEndpoint.cs

@@ -15,7 +15,7 @@ public class GetRecentInquiriesEndpoint : Endpoint<RecentInquiriesQuery, RecentI
     public override void Configure()
     {
         Get("/api/admin-dashboard/recent-inquiries");
-        Policies("Bearer");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(RecentInquiriesQuery request, CancellationToken ct)

src/TaxBaik.Web/Endpoints/AdminDashboard/GetSummaryEndpoint.cs

@@ -15,7 +15,7 @@ public class GetSummaryEndpoint : EndpointWithoutRequest<AdminDashboardSummaryRe
     public override void Configure()
     {
         Get("/api/admin-dashboard/summary");
-        Policies("Bearer");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(CancellationToken ct)

src/TaxBaik.Web/Endpoints/AdminDashboard/GetUpcomingFilingsEndpoint.cs

@@ -15,7 +15,7 @@ public class GetUpcomingFilingsEndpoint : Endpoint<UpcomingFilingsQuery, Upcomin
     public override void Configure()
     {
         Get("/api/admin-dashboard/upcoming-filings");
-        Policies("Bearer");
+        Policies("AdminOnly");
     }
 
     public override async Task HandleAsync(UpcomingFilingsQuery request, CancellationToken ct)

src/TaxBaik.Web/Program.cs

@@ -69,6 +69,10 @@ builder.Services.AddAuthorization(opts =>
     opts.AddPolicy("Bearer", new Microsoft.AspNetCore.Authorization.AuthorizationPolicyBuilder(JwtBearerDefaults.AuthenticationScheme)
         .RequireAuthenticatedUser()
         .Build());
+    opts.AddPolicy("AdminOnly", new Microsoft.AspNetCore.Authorization.AuthorizationPolicyBuilder(JwtBearerDefaults.AuthenticationScheme)
+        .RequireAuthenticatedUser()
+        .RequireRole("Admin")
+        .Build());
 });
 builder.Services.AddProblemDetails();
 builder.Services.AddHealthChecks();

src/TaxBaik.Web/Services/AuthService.cs

@@ -173,7 +173,8 @@ public class AuthService
         {
             new Claim(ClaimTypes.NameIdentifier, user.Id.ToString()),
             new Claim(ClaimTypes.Name, user.Username),
-            new Claim("username", user.Username)
+            new Claim("username", user.Username),
+            new Claim(ClaimTypes.Role, "Admin")
         };
 
         var accessToken = new JwtSecurityToken(

src/TaxBaik.Web/wwwroot/css/admin.css

@@ -497,6 +497,9 @@ textarea:focus-visible {
   border-right: 1px solid var(--border-color);
   display: flex;
   flex-direction: column;
+  position: sticky;
+  top: 0;
+  height: 100vh;
 }
 
 .admin-drawer-brand {
@@ -539,6 +542,23 @@ textarea:focus-visible {
   font-size: 0.78rem;
 }
 
+.admin-nav .mud-nav-link .mud-stack {
+  width: 100%;
+  gap: 8px;
+}
+
+.admin-nav-badge {
+  margin-left: auto;
+  height: 18px;
+  font-size: 0.65rem;
+}
+
+.admin-body {
+  display: flex;
+  min-height: 0;
+  flex: 1;
+}
+
 .admin-nav .mud-nav-group-header {
   min-height: 32px;
   font-size: 0.78rem;
@@ -618,6 +638,130 @@ textarea:focus-visible {
   width: 100%;
 }
 
+.admin-dashboard-grid {
+  margin-top: 0;
+}
+
+.admin-stats-grid {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 12px;
+}
+
+.admin-stat {
+  padding: 14px;
+  border: 1px solid var(--border-color-light);
+  border-radius: var(--radius-lg);
+  background: linear-gradient(180deg, #fff 0%, #f8fbff 100%);
+}
+
+.admin-stat-label {
+  display: block;
+  margin-bottom: 4px;
+  color: var(--text-secondary);
+  font-size: 0.75rem;
+}
+
+.admin-stat-value {
+  font-size: 1.25rem;
+  font-weight: 700;
+  color: var(--text-primary);
+}
+
+.admin-chart {
+  margin-top: 14px;
+  padding: 14px;
+  border: 1px solid var(--border-color-light);
+  border-radius: var(--radius-lg);
+  background: #fff;
+}
+
+.admin-chart-header {
+  display: flex;
+  justify-content: space-between;
+  gap: 12px;
+  margin-bottom: 12px;
+  font-size: 0.8rem;
+  color: var(--text-secondary);
+}
+
+.admin-chart-bars {
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+}
+
+.admin-chart-row {
+  display: grid;
+  grid-template-columns: 56px 1fr 28px;
+  gap: 10px;
+  align-items: center;
+  font-size: 0.75rem;
+}
+
+.admin-chart-track {
+  height: 10px;
+  background: var(--bg-tertiary);
+  border-radius: var(--radius-full);
+  overflow: hidden;
+}
+
+.admin-chart-fill {
+  height: 100%;
+  border-radius: inherit;
+}
+
+.admin-quick-grid {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 12px;
+}
+
+.admin-quick-card {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 14px;
+  border: 1px solid var(--border-color-light);
+  border-radius: var(--radius-lg);
+  cursor: pointer;
+  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
+  background: linear-gradient(180deg, #fff 0%, #f8fbff 100%);
+}
+
+.admin-quick-card:hover {
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-md);
+  border-color: var(--border-color-strong);
+}
+
+.admin-quick-card .mud-icon-root {
+  color: var(--primary-color);
+}
+
+.admin-note-list {
+  display: grid;
+  gap: 10px;
+  color: var(--text-secondary);
+  font-size: 0.8rem;
+}
+
+.admin-note-list div {
+  padding-left: 14px;
+  position: relative;
+}
+
+.admin-note-list div::before {
+  content: '';
+  position: absolute;
+  left: 0;
+  top: 0.55em;
+  width: 6px;
+  height: 6px;
+  border-radius: 9999px;
+  background: var(--primary-color);
+}
+
 /* ============================================================================
    Dashboard Page Styles
    ============================================================================ */