Summary

Add integration tests for shuttle chrome bookmarks CLI (fixture paths, no live Chrome GUI).

Parent: #24

Scope

• Extend tests/test_chrome_commands.py with CLI runner coverage
• Use SHUTTLE_SKIP_CHROME_AUTOMATION=1 and temp bookmarks_file / downloads_dir
• Cover missing backup file on export-to-Chrome path
• Register scenarios in public_endpoints.py if missing

Verification

• Tests pass in Docker ./scripts/test-integration.sh
• No dependency on host Chrome install in CI

Execution

@gh-issue-execute → tests → @gh-pr