fix(HAI-066): remove console.log for file overlap deferral in scheduler

- Remove console.log statement when deferring tasks due to file overlap
- Add test verifying no console.log is emitted on file overlap deferral

packages/engine/src/scheduler.ts

@@ -249,9 +249,6 @@ export class Scheduler {
               }
             }
             if (overlappingTaskId) {
-              console.log(
-                `[scheduler] Deferring ${task.id}: file overlap with ${overlappingTaskId}`,
-              );
               await this.store.updateTask(task.id, { status: "queued", blockedBy: overlappingTaskId });
               continue;
             }