convertClaudeToCodexMarkdown() was missing path replacement — unlike
Copilot/Gemini/Antigravity converters which all replace $HOME/.claude/
paths. This left hardcoded .claude references in Codex agent files,
causing ENOENT when gsd-tools.cjs tried to load from ~/.claude/ on
Codex installations.
Closes#1430
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>