feat: Add custom crun root and enhance container lifecycle

- Use custom `crun --root` for all container commands
- Implement `cleanup_crun_state` for factory reset
- Add retry logic for `crun create` on "File exists" error
- Improve OCI config with `set_terminal`, unique env/rlimits
- Add default mounts for `/dev/pts`, `/dev/shm`, `/dev/mqueue`, `/sys/fs/cgroup`

lib/virt/heropods/container_create.v

@@ -93,6 +93,7 @@ fn (mut self ContainerFactory) create_crun_config(container_name string, rootfs_
 	mut config := crun.new(mut self.crun_configs, name: container_name)!
 
 	// Configure for heropods use case - disable terminal for background containers
+	config.set_terminal(false)
 	config.set_command(['/bin/sh', '-c', 'while true; do sleep 30; done'])
 	config.set_working_dir('/')
 	config.set_user(0, 0, [])