Bring the ZCode integration in line with the other tools: the 243 generated
agent files (integrations/zcode/agents/*.md) are output of `convert.sh`, not
source — add a .gitignore rule so they can't be committed, and add
integrations/zcode/README.md documenting generate/install (matching the vibe
and qwen integration READMEs).
Verified: generated agents are now git-ignored, the README is tracked, and
check-tools.sh still passes at 16 tools.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WKnDRWM4izsB8WAXKszhsq