docs: clarify release agent contract

docs/skills/release.md

@@ -4,6 +4,12 @@ Land a release **through a pull request**, in one run: bump every version locati
 repo declares, regenerate the changelog, open a release PR, let the forge merge it once
 its checks pass, and tag the commit that actually landed.
 
+`/rhiza:release` is the Claude Code entry point for a repo-owned release contract, not a
+Claude-only release policy. The contract is the sequence this page documents — declared
+version locations, changelog evidence, a release PR, a forge-gated merge, and a tag on
+the merged default-branch commit — so another agent or a human runbook can reproduce the
+same pre-tag state without depending on Claude-specific wording.
+
 ```
 /rhiza:release [version e.g. v1.4.0]
 ```

plugin/skills/release/SKILL.md

@@ -9,6 +9,14 @@ You are running `/release` in the **current working directory's repo**. Goal: la
 version bump on the default branch **through a pull request**, like every other change,
 and tag the commit that actually merged — in **one run**.
 
+**This command is the Claude Code harness for a repo-owned release contract, not a
+Claude-only release policy.** The durable contract is the state machine below: declared
+version locations, conventional-commit changelog evidence, a release PR, forge-gated
+merge, and a tag on the merged default-branch commit. Keep the steps explainable in
+those repo terms so another agent, a human following the docs, or a future non-Claude
+wrapper can reproduce the same pre-tag state instead of depending on Claude-specific
+wording.
+
 **A tag still cannot be cut before the merge, which is why there is a wait in the
 middle.** A tag must point at a commit that exists on the branch you publish from; a
 squash-merge replaces the branch's commits with a new one, so a tag created before the