- Add install-command helper (getInstallCommand + platform detection)
with OS-specific one-liners and configurable base URL
- Show onboarding card on Overview when !hostConnected: copy button,
platform switcher (macOS/Linux / Windows), and "Check again" button
- "Check again" triggers refresh and shows success/disconnected toast
- refresh() returns state so callers can react to hostConnected
- Add unit tests for install-commands (all platforms, base URL)
- Document "Native host not found" flow in README and INSTALLATION
