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/tests/components/settings/SessionCard.test.tsx

@@ -134,9 +134,7 @@ describe('SessionCard', () => {
   });
 
   it('highlights current session with border', () => {
-    const { container } = render(
-      <SessionCard session={currentSession} onRevoke={mockOnRevoke} />
-    );
+    const { container } = render(<SessionCard session={currentSession} onRevoke={mockOnRevoke} />);
 
     const card = container.querySelector('.border-primary');
     expect(card).toBeInTheDocument();