refinery: enable auto-merge on PR after validation

examples/gastown/gastown_test.go

@@ -259,6 +259,24 @@ func TestRefineryFormulaRespectsExistingPRMetadata(t *testing.T) {
 	)
 }
 
+func TestRefineryFormulaEnablesAutoMergeAfterPRValidation(t *testing.T) {
+	dir := exampleDir()
+	path := filepath.Join(dir, "packs", "gastown", "formulas", "mol-refinery-patrol.toml")
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading refinery formula: %v", err)
+	}
+	body := string(data)
+	if !strings.Contains(body, `gh pr merge "$PR_REF" --auto`) {
+		t.Errorf("refinery formula missing auto-merge enablement after PR validation")
+	}
+	assertContainsInOrder(t, body,
+		`PR_HEAD_REPO=$(printf '%s\n' "$PR_INFO" | jq -r '.headRepositoryOwner.login + "/" + .headRepository.name')`,
+		`gh pr merge "$PR_REF" --auto`,
+		`gc bd close $WORK --reason "Pull request ready: $PR_URL"`,
+	)
+}
+
 func TestWorktreeSetupKeepsIgnoresLocal(t *testing.T) {
 	tmp := t.TempDir()
 	repo := filepath.Join(tmp, "repo")

examples/gastown/packs/gastown/formulas/mol-refinery-patrol.toml

@@ -515,7 +515,18 @@ fi
 ```
 If this command fails or prints empty output: STOP. Debug and retry. Do NOT continue.
 
-**4. Record PR metadata and close the work bead:**
+**4. Enable auto-merge on the pull request:**
+```bash
+gh pr merge "$PR_REF" --auto -m 2>&1 || true
+```
+Idempotent — `--auto` returns 'already queued' or 'already enabled' on repeat
+calls. If the PR is currently mergeable (all required checks passed), it is
+added directly to the GitHub merge queue; otherwise auto-merge is enabled and
+the PR enters the queue when checks pass. This is best-effort — a transient
+failure here does not block the bead handoff. The intent is that no campaign
+PR sits CI-green-but-unqueued waiting for a human to push the merge button.
+
+**5. Record PR metadata and close the work bead:**
 ```bash
 gc bd update $WORK \
   --set-metadata merge_result=pull_request \
@@ -525,7 +536,7 @@ gc bd update $WORK \
 gc bd close $WORK --reason "Pull request ready: $PR_URL"
 ```
 
-**5. Cleanup:**
+**6. Cleanup:**
 ```bash
 git checkout "$TARGET"
 git branch -d temp