fix: restore watcher elapsed status updates

src/task-scheduler.test.ts

@@ -134,18 +134,48 @@ Check the run.
       } as any,
       phase: 'waiting',
       checkedAt: '2026-03-19T07:02:10.000Z',
+      statusStartedAt: '2026-03-19T07:00:00.000Z',
       nextRun: '2026-03-19T07:04:10.000Z',
     });
 
     expect(rendered).toContain('CI 감시 중: GitHub Actions run 123456');
     expect(rendered).toContain('- 상태: 대기 중');
     expect(rendered).toContain('- 마지막 확인: 16시 02분 10초');
+    expect(rendered).toContain('- 경과 시간: 2분 10초');
     expect(rendered).toContain('- 확인 간격: 1분');
     expect(rendered).toContain('- 다음 확인: 16시 04분 10초');
     expect(rendered).not.toContain('16:02:10');
     expect(rendered).not.toContain('16:04:10');
   });
 
+  it('omits watcher elapsed time when tracking has not started yet', () => {
+    const prompt = `
+[BACKGROUND CI WATCH]
+
+Watch target:
+GitHub Actions run 123456
+
+Task ID:
+task-123
+
+Check instructions:
+Check the run.
+`.trim();
+
+    const rendered = renderWatchCiStatusMessage({
+      task: {
+        prompt,
+        schedule_type: 'interval',
+        schedule_value: '60000',
+      } as any,
+      phase: 'checking',
+      checkedAt: '2026-03-19T07:02:10.000Z',
+      statusStartedAt: null,
+    });
+
+    expect(rendered).not.toContain('- 경과 시간:');
+  });
+
   it('computeNextRun anchors interval tasks to scheduled time to prevent drift', () => {
     const scheduledTime = new Date(Date.now() - 2000).toISOString(); // 2s ago
     const task = {

src/task-scheduler.ts

@@ -140,10 +140,28 @@ function formatWatchIntervalLabel(
   return minutes > 0 ? `${hours}시간 ${minutes}분` : `${hours}시간`;
 }
 
+function formatElapsedLabel(startedAtIso: string, checkedAtIso: string): string {
+  const elapsedMs = Math.max(
+    0,
+    new Date(checkedAtIso).getTime() - new Date(startedAtIso).getTime(),
+  );
+  const totalSeconds = Math.floor(elapsedMs / 1000);
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = totalSeconds % 60;
+
+  const parts: string[] = [];
+  if (hours > 0) parts.push(`${hours}시간`);
+  if (minutes > 0) parts.push(`${minutes}분`);
+  parts.push(`${seconds}초`);
+  return parts.join(' ');
+}
+
 export function renderWatchCiStatusMessage(args: {
   task: Pick<ScheduledTask, 'prompt' | 'schedule_type' | 'schedule_value'>;
   phase: WatcherStatusPhase;
   checkedAt: string;
+  statusStartedAt?: string | null;
   nextRun?: string | null;
 }): string {
   const target = extractWatchCiTarget(args.task.prompt) || 'CI watcher';
@@ -165,6 +183,11 @@ export function renderWatchCiStatusMessage(args: {
     `- 상태: ${statusLabel}`,
     `- 마지막 확인: ${formatTimeLabel(args.checkedAt)}`,
   ];
+  if (args.statusStartedAt) {
+    lines.push(
+      `- 경과 시간: ${formatElapsedLabel(args.statusStartedAt, args.checkedAt)}`,
+    );
+  }
   const intervalLabel = formatWatchIntervalLabel(args.task);
   if (intervalLabel) {
     lines.push(`- 확인 간격: ${intervalLabel}`);
@@ -290,6 +313,7 @@ async function runTask(
       task,
       phase,
       checkedAt,
+      statusStartedAt,
       nextRun,
     });
     const payload = `${TASK_STATUS_MESSAGE_PREFIX}${text}`;