Improvements to pulse-sensor-proxy:
- Fix cluster discovery to use pvecm status for IP addresses instead of node names
- Add standalone node support for non-clustered Proxmox hosts
- Enhanced SSH key push with detailed logging, success/failure tracking, and error reporting
- Add --pulse-server flag to installer for custom Pulse URLs
- Configure www-data group membership for Proxmox IPC access
UI and API cleanup:
- Remove unused "Ensure cluster keys" button from Settings
- Remove /api/diagnostics/temperature-proxy/ensure-cluster-keys endpoint
- Remove EnsureClusterKeys method from tempproxy client
The setup script already handles SSH key distribution during initial configuration,
making the manual refresh button redundant.
