fix(document-release): one canonical spawned contract, downstream notes are pointers

The diff-selected LLM-judge eval scored the skill's clarity 3 (threshold
4, main scores 4): the spawned-session rules read as three separately-
framed rule sets (contract paragraph, Step 8.4d note, Codex-review skip).
The contract paragraph now declares itself the single source of spawned
behavior and the two downstream notes reference it instead of restating
rationale. The pointer avoids naming the Codex section verbatim so the
codex-host render (which strips that section) keeps its negative pin.
Judge re-scored 4/5/4 across repeated samples after the change.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/resolvers/review.ts

@@ -764,11 +764,10 @@ checks the docs against what actually shipped. This is a standard part of /docum
 not an opt-in. The user turns it off only by asking explicitly
 (\`gstack-config set codex_reviews disabled\`).
 
-**Spawned-session skip:** if this session is spawned (\`SESSION_KIND: spawned\` echoed by the
-preamble, or your dispatch prompt marks it — e.g. dispatched from /ship Step 18), skip this
-entire section: the dispatching workflow owns its own review passes, and the apply gate below
-needs a human. Note the skip in your completion report and continue with Step 9's doc health
-summary.
+**Spawned-session skip** (per the spawned-dispatch contract at the top of this skill): in a
+spawned session, skip this entire section — the dispatching workflow owns its own review
+passes, and the apply gate below needs a human. Note the skip in your completion report and
+continue with Step 9's doc health summary.
 
 **Preflight — decide whether and how the doc review runs:**