fix(search): themed highlight in the command palette (accent tint instead of browser yellow)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/components/CommandPalette.tsx

@@ -35,7 +35,7 @@ const SnippetRenderer: React.FC<{ snippet: string }> = ({ snippet }) => {
           return (
             <mark
               key={i}
-              className="bg-accent/25 text-accent font-semibold px-0.5 rounded"
+              className="bg-accent-dim text-accent font-semibold px-0.5 rounded"
             >
               {text}
             </mark>