Setup ystack

Portability (required)

1. Read ../pstack/references/capability-contract.md, ../pstack/references/model-override.schema.json, and the active adapter.
2. Prefer the ystack-named override beside the active agent:
   • Cursor: ~/.cursor/rules/ystack-models.mdc or a project .cursor/rules/ file;
   • Codex: ~/.codex/rules/ystack-models.md;
   • Claude Code / generic: a host-supported user rule or ~/.agents/ystack-models.md.
3. Read legacy files as fallback when the preferred file does not exist:
   • pstack-models.mdc / pstack-models.md;
   • Codex may also honor codex-pstack-models.md.
4. Never invent model slugs. Write only slugs confirmed available in this session.
5. Validate with python3 scripts/validate_model_override.py <path> when the script is available; otherwise self-check against the schema.

Goal

Write a ystack model override that maps model_role values and panel arrays to host models. Missing roles and values set to inherit-parent or auto inherit the parent session behavior.