feat: Cmd+K Enter applies full-text search to dashboard

When pressing Enter in the command palette without explicitly selecting
a result (via arrow keys or mouse), the search query is now applied as
a server-side full-text filter on the Dashboard table. Explicit
selection still navigates to the exchange. Updates design system to
v0.1.18 for the new onSubmit prop.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/LayoutShell.tsx

@@ -199,6 +199,14 @@ function LayoutContent() {
     setPaletteOpen(false);
   }, [navigate, setPaletteOpen]);
 
+  const handlePaletteSubmit = useCallback((query: string) => {
+    // Navigate to dashboard with full-text search applied
+    const currentPath = location.pathname;
+    // Stay on the current app/route context if we're already there
+    const basePath = currentPath.startsWith('/apps/') ? currentPath.split('/').slice(0, 4).join('/') : '/apps';
+    navigate(`${basePath}?text=${encodeURIComponent(query)}`);
+  }, [navigate, location.pathname]);
+
   return (
     <AppShell
       sidebar={
@@ -217,6 +225,7 @@ function LayoutContent() {
         onClose={() => setPaletteOpen(false)}
         onOpen={() => setPaletteOpen(true)}
         onSelect={handlePaletteSelect}
+        onSubmit={handlePaletteSubmit}
         onQueryChange={setPaletteQuery}
         data={searchData}
       />