## Description Replace the current query parameter-based navigation (e.g. `?page=builder`) with proper URL paths (e.g. `/builder`). Update the navbar's styling and code structure to improve usability, maintainability, and consistency across the application. ## Acceptance criteria - [ ] Replace query parameter navigation with path-based routing. - [ ] All existing pages and navigation links work with the new routes. - [ ] Direct links and browser refreshes work on all pages. - [ ] Browser back and forward navigation works correctly. - [ ] Refactor the navbar code to improve readability and maintainability. - [ ] Update the navbar styling for a more consistent design. - [ ] Ensure the navbar works on both mobile and desktop. - [ ] Existing functionality remains unaffected. ## Dependencies - Existing frontend pages and navigation components. - Routing configuration must support direct URL access on the deployed VM.