M1: snapshot carries session_id and outcome_pending

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

internal/store/store.go

@@ -17,6 +17,8 @@ type Snapshot struct {
 	RuntimeState     domain.RuntimeState `json:"runtime_state"`
 	Commitment       *domain.Commitment  `json:"commitment,omitempty"`
 	DeadlineUnixSecs int64               `json:"deadline_unix_secs,omitempty"`
+	SessionID        string              `json:"session_id,omitempty"`
+	OutcomePending   string              `json:"outcome_pending,omitempty"`
 }
 
 // DefaultPath returns ~/.antidrift/state.json.

internal/store/store_test.go

@@ -48,3 +48,22 @@ func TestSaveThenLoadRoundTrips(t *testing.T) {
 		t.Errorf("deadline: got %d want %d", got.DeadlineUnixSecs, want.DeadlineUnixSecs)
 	}
 }
+
+func TestSnapshotCarriesSessionFields(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "state.json")
+	want := Snapshot{
+		RuntimeState:   domain.RuntimeActive,
+		SessionID:      "session-abc",
+		OutcomePending: "completed",
+	}
+	if err := Save(path, want); err != nil {
+		t.Fatalf("save: %v", err)
+	}
+	got, err := Load(path)
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	if got.SessionID != "session-abc" || got.OutcomePending != "completed" {
+		t.Fatalf("session fields did not round-trip: %+v", got)
+	}
+}