feat: add shared workspace layouts

webui/tests/page-layout.test.tsx

@@ -46,3 +46,33 @@ assert(!embeddedMarkup.includes("page-scroll-viewport"), "embedded pages defer s
 assert(!embeddedMarkup.includes("content-pad"), "embedded pages do not add a second content inset");
 assert(embeddedMarkup.includes("page-layout-embedded"), "embedded mode remains explicit");
 assert(embeddedMarkup.includes('data-help-documentation-type="admin"'), "embedded administration keeps its documentation type");
+
+const workspaceMarkup = renderToStaticMarkup(
+  <PlatformLanguageProvider>
+    <PageLayout
+      title="Workspace page"
+      description={<p className="version-line">Version 3</p>}
+      mode="workspace"
+      notices={<div role="status">Additional notice</div>}
+    >
+      Workspace content
+    </PageLayout>
+  </PlatformLanguageProvider>
+);
+
+assert(!workspaceMarkup.includes("page-scroll-viewport"), "workspace pages defer scrolling to the workspace content pane");
+assert(workspaceMarkup.includes("page-layout-workspace content-pad workspace-data-page"), "workspace pages keep the standard content inset");
+assert(workspaceMarkup.includes('class="version-line"'), "rich page descriptions keep their own semantic element");
+assert(!workspaceMarkup.includes("<p><p"), "rich page descriptions are not nested in an invalid paragraph");
+assert(workspaceMarkup.includes("page-layout-notices"), "additional page notices use the central notice region");
+
+const headerLoadingMarkup = renderToStaticMarkup(
+  <PlatformLanguageProvider>
+    <PageLayout title="Refreshing" mode="workspace" headerLoading>
+      Stable content
+    </PageLayout>
+  </PlatformLanguageProvider>
+);
+
+assert(headerLoadingMarkup.includes("loading-indicator"), "page headings can expose partial refresh progress");
+assert(!headerLoadingMarkup.includes('aria-busy="true"'), "partial refresh does not block the stable page body");