remove outdated commands: preflight, utils, self legacy group

preflight referenced non-existent work-order.md (replaced by agent-tasks.md).
utils only contained albany-cleanup (Albany supercomputer no longer used).
self was a legacy backward-compat group — update/uninstall are already top-level.

bin/commands/self_mgmt.py

@@ -107,12 +107,3 @@ def uninstall_cmd():
     click.secho("mytoolkit removed.", fg="green")
 
 
-# Backward compatibility: keep self_cmd group for any existing scripts
-@click.group(name="self")
-def self_cmd():
-    """Manage mytoolkit itself (legacy, use 'update'/'uninstall' directly)."""
-    pass
-
-
-self_cmd.add_command(update_cmd, name="update")
-self_cmd.add_command(uninstall_cmd, name="uninstall")