- Tool description and param schema now use 'commands' (matching ExecuteMultipleDeviceCommands)
- Updated error message in handler
- Clarified in docstring that this is read-only; use device_config_send for config changes
config_tools_nornir expects config_commands, while
display_tools_nornir and vpcs_tools_netmiko expect commands.
Render template now uses the correct field name.
- Add optional 'template' param with Jinja2 syntax
- Each device entry can use 'vars' dict instead of 'config_commands'
- Template rendered per device, merged with existing commands
- Rendering errors returned inline for AI self-correction
