Add tablet navigation drawer to shell

src/RolemasterDb.App/Components/Shell/AppShell.razor.css

@@ -103,6 +103,28 @@
     min-height: 2.75rem;
 }
 
+.app-shell-menu-toggle {
+    display: none;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 0.24rem;
+    width: 2.75rem;
+    height: 2.75rem;
+    border: 1px solid var(--border-default);
+    border-radius: 16px;
+    background: color-mix(in srgb, var(--surface-2) 84%, transparent);
+    color: var(--text-primary);
+    padding: 0;
+}
+
+.app-shell-menu-toggle-bar {
+    width: 1rem;
+    height: 2px;
+    border-radius: 999px;
+    background: currentColor;
+}
+
 .app-shell-shortcuts {
     margin-top: 0.75rem;
 }
@@ -128,6 +150,55 @@
     margin-top: auto;
 }
 
+.app-shell-drawer-backdrop {
+    position: fixed;
+    inset: 0;
+    z-index: 45;
+    border: none;
+    background: var(--bg-overlay);
+    padding: 0;
+}
+
+.app-shell-drawer {
+    position: fixed;
+    top: 1rem;
+    right: 1rem;
+    z-index: 50;
+    width: min(24rem, calc(100vw - 2rem));
+    padding: 1rem;
+    border: 1px solid var(--border-default);
+    border-radius: 24px;
+    background: color-mix(in srgb, var(--bg-elevated) 94%, transparent);
+    box-shadow: var(--shadow-2);
+    backdrop-filter: blur(18px);
+}
+
+.app-shell-drawer .shell-primary-nav {
+    flex-direction: column;
+    align-items: stretch;
+}
+
+.app-shell-drawer .shell-primary-nav-link {
+    justify-content: flex-start;
+}
+
+.app-shell-drawer-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 0.75rem;
+    margin-bottom: 0.75rem;
+}
+
+.app-shell-drawer-close {
+    border: 1px solid var(--border-default);
+    border-radius: 999px;
+    background: color-mix(in srgb, var(--surface-2) 84%, transparent);
+    color: var(--text-primary);
+    min-height: 2.5rem;
+    padding: 0.45rem 0.85rem;
+}
+
 @media (max-width: 767.98px) {
     .app-shell-header {
         padding: 0.65rem 0.75rem 0;
@@ -170,4 +241,15 @@
     .app-shell-header-nav {
         display: none;
     }
+
+    .app-shell-menu-toggle {
+        display: inline-flex;
+    }
+}
+
+@media (min-width: 1024px) {
+    .app-shell-drawer,
+    .app-shell-drawer-backdrop {
+        display: none;
+    }
 }