chore: add test report directories to gitignore

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -22,3 +22,8 @@ dist-ssr
 *.njsproj
 *.sln
 *.sw?
+
+# Test reports
+playwright-report/
+test-results/
+coverage/