Codex-generated skill preambles hardcode ~/.Codex while installer exposes ~/.agents #2338

Summary

In a Codex session using gstack 0.16.2.0 at commit dbd7aee5b6b5bb41b17ae7747568e2fda8a91d77, the generated review/SKILL.md preamble invokes ~/.Codex/skills/gstack/bin/gstack-config. The installed skill and binaries are under ~/.agents/skills/gstack, so every such invocation fails.

Exact error

/bin/bash: /home/maxlab/.Codex/skills/gstack/bin/gstack-config: No such file or directory

Reproduction

1. Install/expose gstack to Codex under ~/.agents/skills/gstack.
2. Invoke the generated review skill.
3. Run the required preamble.
4. Observe calls to ~/.Codex/skills/gstack/bin/gstack-config fail even though ~/.agents/skills/gstack/bin/gstack-config exists and is executable.

Proof:

ls: cannot access /home/maxlab/.Codex/skills/gstack/bin/gstack-config: No such file or directory
-rwxr-xr-x /home/maxlab/.agents/skills/gstack/bin/gstack-config

Root cause

The Codex-generated SKILL body hardcodes a host path/capitalization that does not match the actual installed skill root supplied to the session. This is related to #1882 and #1163, but the concrete mismatch here is .Codex versus .agents, not only a renamed checkout.

Impact

Skill config, telemetry, learnings, timelines, and preference prompts silently fail or emit shell errors. The review itself can continue only by manually substituting the actual install root.

Expected

Generated skill bodies should resolve their own package root or use the actual host install root from setup, with a regression test that executes the preamble from a Codex ~/.agents/skills install.