feat(FN-5052): complete Step 4 — gate in-review stall surfacing on autoMerge

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

packages/engine/src/self-healing.ts

@@ -3578,6 +3578,7 @@ export class SelfHealingManager {
     try {
       const settings = await this.store.getSettings();
       if (settings.globalPause || settings.enginePaused) return 0;
+      if (!settings.autoMerge) return 0;
 
       const cycleStartMs = Date.now();
       const timeoutMs = settings.taskStuckTimeoutMs;