Include Qwen in skill command help text to accurately reflect supported AI assistants

The skill command help text was missing Qwen from the list of supported AI assistants,
even though Qwen is fully supported throughout the codebase. This update ensures
the CLI documentation correctly represents all available options.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: James Zhu

code_assistant_manager/cli/skills_commands.py

@@ -19,7 +19,7 @@
 logger = logging.getLogger(__name__)
 
 skill_app = typer.Typer(
-    help="Manage skills for AI assistants (Claude, Codex, Copilot, Gemini, Droid, CodeBuddy)",
+    help="Manage skills for AI assistants (Claude, Codex, Copilot, Gemini, Droid, CodeBuddy, Qwen)",
     no_args_is_help=True,
 )