- Add --upgrade flag that detects existing installations and skips clone/build/register
- Add global trap-based cleanup (register_cleanup_dir + cleanup_on_exit) for temp dirs
- Add check_git() with platform-specific install suggestions (xcode-select on macOS, apt on Linux)
- Add check_port_37777() to detect worker already running before starting a new one
- Add is_claude_mem_installed() for upgrade detection via plugin directory check
- Add ensure_jq_or_fallback() utility for JSON operations with jq/node fallback
- All 160 tests pass (23 new tests for error handling functions)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Alex Newman
cb6ff8738b