* fix: SDK Agent fails on Windows when username contains spaces
Fixes spawn failure on Windows when the user's path contains spaces
(e.g., C:\Users\Anderson Wang\).
Root cause:
- SDKAgent.ts returns full auto-detected path with spaces
- ProcessRegistry.ts cannot execute .cmd files when path contains spaces
Solution:
- SDKAgent: On Windows, prefer "claude.cmd" via PATH instead of full path
- ProcessRegistry: Use cmd.exe /d /c wrapper for .cmd files on Windows
This preserves argument boundaries (e.g., empty string values) while
properly handling paths with spaces.
Fixes#1014
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* docs: add Windows spawn path with spaces fix documentation
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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
