Refactor useAuth hook, settings components, and docs for formatting and readability improvements

- Consolidated multi-line arguments into single lines where appropriate in `useAuth`.
- Improved spacing and readability in data processing across components (`ProfileSettingsForm`, `PasswordChangeForm`, `SessionCard`).
- Applied consistent table and markdown formatting in design system docs (e.g., `README.md`, `08-ai-guidelines.md`, `00-quick-start.md`).
- Updated code snippets to ensure adherence to Prettier rules and streamlined JSX structures.

frontend/src/app/page.tsx

@@ -99,10 +99,7 @@ export default function Home() {
       </footer>
 
       {/* Shared Demo Credentials Modal */}
-      <DemoCredentialsModal
-        open={demoModalOpen}
-        onClose={() => setDemoModalOpen(false)}
-      />
+      <DemoCredentialsModal open={demoModalOpen} onClose={() => setDemoModalOpen(false)} />
     </div>
   );
 }