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/theme/ThemeToggle.tsx

@@ -22,11 +22,7 @@ export function ThemeToggle() {
     <DropdownMenu>
       <DropdownMenuTrigger asChild>
         <Button variant="ghost" size="icon" aria-label="Toggle theme">
-          {resolvedTheme === 'dark' ? (
-            <Moon className="h-5 w-5" />
-          ) : (
-            <Sun className="h-5 w-5" />
-          )}
+          {resolvedTheme === 'dark' ? <Moon className="h-5 w-5" /> : <Sun className="h-5 w-5" />}
         </Button>
       </DropdownMenuTrigger>
       <DropdownMenuContent align="end">