fix: migrate Qwen Code CLI from TOML to Markdown format (#1589)

Qwen Code CLI v0.10.0 deprecated TOML format and fully switched to
Markdown as the core format for configuration and interaction files.

- Update create-release-packages.sh: generate .md files with $ARGUMENTS
  instead of .toml files with {{args}} for qwen agent
- Update create-release-packages.ps1: same change for PowerShell script
- Update AGENTS.md: reflect Qwen's new Markdown format in docs and
  remove Qwen from TOML format section
- Update tests/test_ai_skills.py: add commands_dir_qwen fixture and
  tests covering Markdown-format skills installation for Qwen

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

Author: fuyongde

AGENTS.md

@@ -337,7 +337,7 @@ Work within integrated development environments:
 
 ### Markdown Format
 
-Used by: Claude, Cursor, opencode, Windsurf, Kiro CLI, Amp, SHAI, IBM Bob
+Used by: Claude, Cursor, opencode, Windsurf, Kiro CLI, Amp, SHAI, IBM Bob, Qwen
 
 **Standard format:**