fix(install): create properly prefixed symlinks for independent skill management

Allow users to identify and uninstall minimax skills without affecting other skills in the same directory.
- Create individual minimax-{skill_name} symlinks instead of single broken link
- Uninstall now removes only minimax-* symlinks, preserving other skills
- Fix Windows PowerShell naming to match
- Add Chinese installation guide (low-priority)

README_zh.md

@@ -63,7 +63,7 @@ mkdir -p ~/.config/opencode/skills
 ln -s ~/.minimax-skills/skills/* ~/.config/opencode/skills/
 ```
 
-重启 OpenCode 以发现技能。详见 [`.opencode/INSTALL.md`](.opencode/INSTALL.md)。
+重启 OpenCode 以发现技能。详见 [`.opencode/INSTALL_zh.md`](.opencode/INSTALL_zh.md)。
 
 ### VS Code