feat: add computer-use-hybrid extension and related skills

[DragonnZhang]

Summary

Introduce a computer-use-hybrid extension that enables Qwen Code to control native macOS desktop applications through accessibility-tree-based interaction, along with the supporting computer-use and browser-use skills.

Changes

New Extension: computer-use-hybrid

• qwen-extension.json — registers the open-computer-use MCP server
• QWEN.md — documents MCP routing rules, requirements (Node.js, macOS permissions), and upstream references
• README.md — user-facing README with installation, usage, and troubleshooting guidance

New Skills

• computer-use-hybrid (SKILL.md) — skill definition for operating native macOS apps via the hybrid MCP server
• computer-use (SKILL.md) — skill for computer control tasks
• browser-use (SKILL.md) — skill for browser automation tasks

Highlights

• AX-tree-first approach: prefer element-based interaction over raw pixel coordinates for reliability
• Clear guidance on macOS Accessibility & Screen Recording permission setup
• Upstream project linked for transparency

Testing

• Manual testing of desktop automation workflows on macOS
• Verified MCP server launch and skill invocation through Qwen Code