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/components/auth/AuthGuard.tsx

@@ -83,9 +83,8 @@ export function AuthGuard({ children, requireAdmin = false, fallback }: AuthGuar
     // If not loading and not authenticated, redirect to login
     if (!isLoading && !isAuthenticated) {
       // Preserve intended destination
-      const returnUrl = pathname !== config.routes.login
-        ? `?returnUrl=${encodeURIComponent(pathname)}`
-        : '';
+      const returnUrl =
+        pathname !== config.routes.login ? `?returnUrl=${encodeURIComponent(pathname)}` : '';
 
       router.push(`${config.routes.login}${returnUrl}`);
     }