chore(gitignore): ignore generated test artifacts

- Add playwright-report* pattern for Playwright test output
- Add tools/scripts/route-coverage-report.md for generated coverage reports

Author: Mearman

.gitignore

@@ -18,6 +18,8 @@ coverage-reports
 
 # Test results and artifacts
 test-results
+playwright-report*
+playwright-report-shard-*/
 
 # Editor directories and files
 .vscode/*
@@ -92,7 +94,6 @@ tools/dist/**/lib/
 graph.json
 
 # Test cache data files (generated during test execution with unified hex encoding)
-
 test-results.json
 
 # Working files protection (Constitution Principle XIV - Working Files Hygiene)
@@ -104,6 +105,9 @@ test-results.json
 *.jpg
 *.jpeg
 
+# Route coverage reports (generated during E2E test verification)
+tools/scripts/route-coverage-report.md
+
 vite.config.*.timestamp*
 vitest.config.*.timestamp*