merge: worktree-a11y-fixes into main

Accessibility fixes (aria-labels, color contrast, html lang, inline link
underlines), atomic dev login endpoints, and E2E test hardening.

app/layouts/admin.vue

@@ -151,6 +151,7 @@
 <script setup>
 const route = useRoute();
 const isMobileMenuOpen = ref(false);
+const { logout } = useAuth();
 
 const pageBreadcrumbTitle = useState("pageBreadcrumbTitle", () => "");
 
@@ -163,15 +164,6 @@ const currentPageName = computed(() => {
   }
   return segments.join(" / ");
 });
-
-const logout = async () => {
-  try {
-    await $fetch("/api/auth/logout", { method: "POST" });
-    await navigateTo("/");
-  } catch (error) {
-    console.error("Logout failed:", error);
-  }
-};
 </script>
 
 <style scoped>