fix: guard HTTP failure responses and rename res to response

- Rename `res` to `response` to follow no-abbreviation naming guideline
- Add `response.ok` check to throw on non-2xx status codes, preventing
  error page content from being silently copied to the clipboard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/header.tsx

@@ -68,8 +68,11 @@ export function Header() {
 							<ContextMenuItem
 								onClick={async () => {
 									try {
-										const res = await fetch(DEFAULT_LOGO_URL);
-										const svg = await res.text();
+										const response = await fetch(DEFAULT_LOGO_URL);
+										if (!response.ok) {
+											throw new Error(`Failed to fetch SVG: ${response.status}`);
+										}
+										const svg = await response.text();
 										await navigator.clipboard.writeText(svg);
 										toast.success("SVG copied to clipboard");
 									} catch {