Agent Context Files

The cross-vendor markdown-as-control-plane pattern: repo-versioned plaintext (CLAUDE.md / AGENTS.md / SOUL.md / WORKFLOW.md / SPEC.md / .cursorrules) that configures agent behavior, split by role across project / personality / workflow / spec layers — and, since Genkit implemented SKILL.md loading in four language SDKs, a convention with a second vendor's runtime behind it as well as its authoring conventions