fix: tolerate runtime schema drift

internal/workflow/store.go

@@ -16,6 +16,14 @@ type Store struct {
 }
 
 func (s Store) View() (View, error) {
+	if s.Runtime == nil {
+		return View{
+			Events:       []Event{},
+			HandoffEdges: []HandoffEdge{},
+			Phases:       []Phase{},
+			Source:       SourceEvidence{Kind: "runtime_missing", Confidence: "low", Message: "Runtime reader is not configured; returning an empty workflow view."},
+		}, nil
+	}
 	snapshot, err := s.Runtime.Snapshot()
 	if err != nil {
 		return View{}, err

internal/workflow/store_test.go

@@ -46,6 +46,19 @@ func TestStoreBuildsDynamicEventsWithoutFixedRoles(t *testing.T) {
 	}
 }
 
+func TestStoreNilRuntimeReturnsEmptyLowConfidenceView(t *testing.T) {
+	view, err := Store{WorkspaceRoot: t.TempDir()}.View()
+	if err != nil {
+		t.Fatalf("View returned error: %v", err)
+	}
+	if len(view.Events) != 0 || len(view.HandoffEdges) != 0 || len(view.Phases) != 0 {
+		t.Fatalf("expected empty view, got %#v", view)
+	}
+	if view.Source.Kind != "runtime_missing" || view.Source.Confidence != "low" {
+		t.Fatalf("unexpected source: %#v", view.Source)
+	}
+}
+
 type StaticRuntime struct {
 	SnapshotValue runtime.Snapshot
 }