fix: allow project removal with incomplete session handles

Author: Vaibhaav

backend/internal/service/session/service.go

@@ -366,13 +366,24 @@ func (s *Service) TeardownProject(ctx context.Context, project domain.ProjectID)
 			continue
 		}
 		if _, err := s.Kill(ctx, rec.ID); err != nil {
+			if isIncompleteHandleError(err) {
+				continue
+			}
 			return err
 		}
 	}
 	_, err = s.Cleanup(ctx, project)
 	return err
 }
 
+func isIncompleteHandleError(err error) bool {
+	if errors.Is(err, sessionmanager.ErrIncompleteHandle) {
+		return true
+	}
+	var apiErr *apierr.Error
+	return errors.As(err, &apiErr) && apiErr.Code == "SESSION_INCOMPLETE_HANDLE"
+}
+
 // List returns sessions as enriched display models after applying API filters.
 func (s *Service) List(ctx context.Context, filter ListFilter) ([]domain.Session, error) {
 	recs, err := s.listRecords(ctx, filter.ProjectID)

backend/internal/service/session/service_test.go

@@ -235,6 +235,20 @@ func TestTeardownProjectStopsOnKillError(t *testing.T) {
 	}
 }
 
+func TestTeardownProjectContinuesOnIncompleteHandle(t *testing.T) {
+	st := newFakeStore()
+	st.sessions["mer-1"] = domain.SessionRecord{ID: "mer-1", ProjectID: "mer"}
+	fc := &fakeCommander{killErr: sessionmanager.ErrIncompleteHandle}
+	svc := &Service{manager: fc, store: st}
+
+	if err := svc.TeardownProject(context.Background(), "mer"); err != nil {
+		t.Fatalf("TeardownProject: %v", err)
+	}
+	if len(fc.cleanupProjects) != 1 || fc.cleanupProjects[0] != "mer" {
+		t.Fatalf("cleanup projects = %#v, want [mer]", fc.cleanupProjects)
+	}
+}
+
 func TestSpawnOrchestratorCleanKillsActiveOrchestratorsBeforeSpawn(t *testing.T) {
 	st := newFakeStore()
 	st.projects["mer"] = domain.ProjectRecord{ID: "mer"}