fix(cron): wait for in-flight jobs on shutdown

docs/project-changelog.md

@@ -6,6 +6,18 @@ Significant changes, features, and fixes in reverse chronological order.
 
 ## 2026-06-12
 
+### Cron scheduler shutdown drain (post-merge CI follow-up)
+
+**Fixes**
+
+- Made cron service shutdown wait for scheduler-launched job executions to
+  finish so in-flight status persistence cannot outlive `Stop()`.
+
+**Tests**
+
+- Added regression coverage proving `Stop()` waits for a blocked in-flight job
+  before returning.
+
 ### Bundled GoClaw gateway administration skill (issue #175)
 
 **Changes**

internal/cron/service.go

@@ -14,6 +14,7 @@ type Service struct {
 	running   bool
 	stopChan  chan struct{}
 	loopWG    sync.WaitGroup
+	jobWG     sync.WaitGroup
 	mu        sync.Mutex
 	runLog    []RunLogEntry // in-memory run history (last 200 entries)
 	retryCfg  RetryConfig   // retry config for failed jobs
@@ -114,6 +115,7 @@ func (cs *Service) Stop() {
 	cs.mu.Unlock()
 
 	cs.loopWG.Wait()
+	cs.jobWG.Wait()
 	slog.Info("cron service stopped")
 }
 

internal/cron/service_execution.go

@@ -209,6 +209,7 @@ func (cs *Service) checkJobs() {
 		}
 	}
 	cs.saveUnsafe()
+	cs.jobWG.Add(len(dueJobs))
 	cs.mu.Unlock()
 
 	// Execute jobs in parallel without blocking the runLoop.
@@ -217,6 +218,7 @@ func (cs *Service) checkJobs() {
 	// due jobs. Now each job runs independently with panic recovery.
 	for _, dj := range dueJobs {
 		go func(id string, scheduledAtMS int64) {
+			defer cs.jobWG.Done()
 			defer safego.Recover(nil, "job_id", id)
 			cs.executeJobByID(id, scheduledAtMS)
 		}(dj.id, dj.scheduledAtMS)

internal/cron/service_test.go

@@ -306,6 +306,55 @@ func TestService_JobFailure_Updates_LastError(t *testing.T) {
 	}
 }
 
+func TestService_Stop_WaitsForInFlightJob(t *testing.T) {
+	setFastTick(t)
+	dir := t.TempDir()
+	storePath := filepath.Join(dir, "cron.json")
+
+	entered := make(chan struct{})
+	release := make(chan struct{})
+	handler := func(job *Job) (string, error) {
+		close(entered)
+		<-release
+		return "done", nil
+	}
+
+	cs := NewService(storePath, handler)
+	interval := int64(10)
+	if _, err := cs.AddJob("blocking", Schedule{Kind: "every", EveryMS: &interval}, "block", false, "", "", ""); err != nil {
+		t.Fatalf("AddJob error: %v", err)
+	}
+	if err := cs.Start(); err != nil {
+		t.Fatalf("Start error: %v", err)
+	}
+
+	select {
+	case <-entered:
+	case <-time.After(time.Second):
+		cs.Stop()
+		t.Fatal("job handler did not start")
+	}
+
+	stopped := make(chan struct{})
+	go func() {
+		cs.Stop()
+		close(stopped)
+	}()
+
+	select {
+	case <-stopped:
+		t.Fatal("Stop returned while job handler was still running")
+	case <-time.After(50 * time.Millisecond):
+	}
+
+	close(release)
+	select {
+	case <-stopped:
+	case <-time.After(time.Second):
+		t.Fatal("Stop did not return after in-flight job completed")
+	}
+}
+
 // --- Persistence: save and reload ---
 
 func TestService_Persistence_Roundtrip(t *testing.T) {