feat(FN-5052): complete Step 2 — gate in-review stall helper on autoMerge

Fusion-Task-Id: FN-5052
Fusion-Task-Lineage: 607cd9e6-e4d0-4572-b183-8253d127209f

packages/core/src/in-review-stall.ts

@@ -7,6 +7,9 @@ import type { Task, TaskLogEntry } from "./types.js";
  *
  * Returning a signal is diagnostic-only and does not trigger any mutation by
  * itself. Callers MUST NOT use this helper as an auto-completion signal.
+ *
+ * When `context.autoMerge === false`, the signal is unconditionally suppressed
+ * because in-review tasks are expected to remain on the PR-based manual flow.
  */
 export type InReviewStallCode =
   | "merge-blocker"
@@ -22,6 +25,7 @@ export interface InReviewStallSignal {
 
 export interface InReviewStallContext {
   now?: number;
+  autoMerge?: boolean;
   activeMergeTaskId?: string | null;
   executingTaskIds?: ReadonlySet<string>;
   staleMergingMinAgeMs?: number;
@@ -73,6 +77,10 @@ export function getInReviewStallReason(
     return undefined;
   }
 
+  if (context.autoMerge === false) {
+    return undefined;
+  }
+
   const now = context.now ?? Date.now();
   const observedAt = new Date(now).toISOString();
   const staleMergingMinAgeMs = context.staleMergingMinAgeMs ?? DEFAULT_STALE_MERGING_MIN_AGE_MS;