fix: resolve npm CLI wrappers in Windows watchers

[haosenwang1018]

Summary

• resolve provider CLI wrappers to their real Node entrypoints before watcher spawn on Windows
• teach both watcher variants to invoke node script.js ...args when the provider binary is an npm-generated .cmd wrapper
• add regression coverage for wrapper detection and spawn spec resolution

Related Issues

Part of #457

Changes Made

• add Windows-aware command lookup helpers in lib/provider-detection.js
• pass the resolved CLI path into watcher config from task-lib/runner.js
• reuse the Windows spawn resolution in both task-lib/watcher.js and task-lib/attachable-watcher.js
• cover where lookup plus .cmd wrapper parsing in tests/providers/detection.test.js

Testing

• ./node_modules/.bin/mocha tests/providers/detection.test.js tests/issue-providers.test.js

Checklist

• Tests pass (npm test)
• Documentation updated (if needed)
• Follows commit guidelines