refactor(templates): rename show to list for CLI consistency

Other subcommand groups (server, env, ssh, webpage, git proxy) use
`list` for enumeration; align templates with the same convention.

bin/commands/templates.py

@@ -21,9 +21,9 @@ def templates_register(path):
     click.secho(f"Registered: {resolved}", fg="green")
 
 
-@templates_cmd.command("show")
-def templates_show():
-    """Show the current registry and available templates."""
+@templates_cmd.command("list")
+def templates_list():
+    """List the current registry and available templates."""
     if not templates_registry.CONFIG_PATH.exists():
         click.echo("No registry. Run: mytoolkit templates register <path>")
         return