enhancement(ui): use consistent keycap styling for search keyboard shortcut

### Summary The search input currently displays the `Ctrl K` keyboard shortcut as plain text, while other keyboard shortcuts in the application (such as **Ask Assistant**) are rendered using keycap-style UI elements. This creates an inconsistency in the interface. <img width="1084" height="843" alt="Image" src="https://github.com/user-attachments/assets/90c16d70-cca7-44bc-a589-aba852d5ecf4" /> ### Current Behavior * The search input displays `Ctrl K` as plain text. * Other keyboard shortcuts use keycap/button-style backgrounds. ### Expected Behavior Render the search keyboard shortcut using the same keycap styling as other shortcuts throughout the application to maintain a consistent visual language. ### Why This Improvement? * Improves visual consistency across the interface. * Makes keyboard shortcuts easier to identify. * Aligns with the existing design system and UX patterns.