refactor: Harden and improve SSH agent module

- Add extensive security validations for SSH agent
- Implement robust `ssh-agent` auto-start script
- Enhance `sshagent` operations with improved error handling
- Revamp `sshagent` test suite for comprehensive coverage
- Update `sshagent` README with detailed documentation

lib/osal/core/net.v

@@ -4,7 +4,6 @@ import net
 import time
 import freeflowuniverse.herolib.ui.console
 import freeflowuniverse.herolib.core
-import os
 
 pub enum PingResult {
 	ok

lib/osal/core/package.v

@@ -3,7 +3,6 @@ module core
 import freeflowuniverse.herolib.ui.console
 import freeflowuniverse.herolib.core.texttools
 import freeflowuniverse.herolib.core
-import os
 
 // update the package list
 pub fn package_refresh() ! {