Remove repeated demo notes from product screens (#28)

frontend/app/lib/workspace/shell.dart

@@ -63,18 +63,14 @@ class _WorkspaceShellState extends State<WorkspaceShell> {
     final wide = MediaQuery.sizeOf(context).width >= 900;
     final content = Column(
       children: [
-        Padding(
-          padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
-          child: Column(
-            crossAxisAlignment: wide
-                ? CrossAxisAlignment.end
-                : CrossAxisAlignment.start,
-            children: [
-              if (!wide) ...[const BrandWordmark(), const SizedBox(height: 8)],
-              Text(l.wDemo, style: t.textTheme.bodySmall),
-            ],
+        if (!wide)
+          const Padding(
+            padding: EdgeInsets.symmetric(horizontal: 24, vertical: 12),
+            child: Align(
+              alignment: Alignment.centerLeft,
+              child: BrandWordmark(),
+            ),
           ),
-        ),
         Expanded(child: widget.child),
       ],
     );