solo/help: fix Python 3.14 argparse positional argument crash

Python 3.14 rejects action='store_true' on positional arguments.
The add_argument calls in _show_help() are display-only (never parsed),
so the action kwarg was unnecessary.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/solo/commands/help.py

@@ -89,7 +89,7 @@ class SoloHelp(SoloCommand):
             name = "%s%s" % (purple(descriptor.get_name()),
                 aliases_str)
             desc = descriptor.get_description()
-            group.add_argument(name, help=darkgreen(desc), action="store_true")
+            group.add_argument(name, help=darkgreen(desc))
         parser.print_help()
         if not self._args:
             return 1