Add runtime and commitment state machines

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

internal/statemachine/statemachine_test.go

@@ -0,0 +1,54 @@
+package statemachine
+
+import (
+	"testing"
+
+	"antidrift/internal/domain"
+)
+
+func TestPlanningActivatesOnlyWithAcceptedPolicy(t *testing.T) {
+	got, err := TransitionRuntime(domain.RuntimePlanning, ActivateAccepted)
+	if err != nil || got != domain.RuntimeActive {
+		t.Fatalf("accepted: got %s err %v", got, err)
+	}
+	_, err = TransitionRuntime(domain.RuntimePlanning, ActivateRejected)
+	if err == nil {
+		t.Fatalf("rejected policy should error")
+	}
+}
+
+func TestActiveCanCompleteForReview(t *testing.T) {
+	got, err := TransitionRuntime(domain.RuntimeActive, CompleteForReview)
+	if err != nil || got != domain.RuntimeReview {
+		t.Fatalf("got %s err %v", got, err)
+	}
+}
+
+func TestReviewEndsToLocked(t *testing.T) {
+	got, err := TransitionRuntime(domain.RuntimeReview, EndWorkPeriod)
+	if err != nil || got != domain.RuntimeLocked {
+		t.Fatalf("got %s err %v", got, err)
+	}
+}
+
+func TestLockedCannotBecomeActiveDirectly(t *testing.T) {
+	_, err := TransitionRuntime(domain.RuntimeLocked, ActivateAccepted)
+	if err == nil {
+		t.Fatalf("locked->active must be illegal")
+	}
+}
+
+func TestCommitmentDraftActivatesAndViolatedRecovers(t *testing.T) {
+	got, err := TransitionCommitment(domain.CommitmentDraft, CommitmentActivate)
+	if err != nil || got != domain.CommitmentActive {
+		t.Fatalf("draft->active: got %s err %v", got, err)
+	}
+	got, err = TransitionCommitment(domain.CommitmentViolated, RecoverExplicitly)
+	if err != nil || got != domain.CommitmentActive {
+		t.Fatalf("violated->active: got %s err %v", got, err)
+	}
+	_, err = TransitionCommitment(domain.CommitmentViolated, ReturnFromPause)
+	if err == nil {
+		t.Fatalf("violated->returnFromPause must be illegal")
+	}
+}