fix: keep terminal false branches structured

Symptom: describe could collapse a real terminal false branch into a guard-style continuation when the branch happened to sit on the split centerline, moving statements outside their original ELSE block.

Root cause: guard continuation detection looked only at layout Y position. That made a branch-shaped false flow indistinguishable from the horizontal split-to-tail flow produced for guard-style IF statements.

Fix: require the false flow to also use the builder's horizontal right-to-left anchor pair before treating it as a guard continuation. Terminal false branches without that guard-tail flow shape remain inside an explicit ELSE.

Tests: make build, make test, make lint-go.

Author: hjothamendix

mdl/executor/cmd_microflows_show_helpers.go

@@ -1442,10 +1442,13 @@ func flowLooksLikeGuardContinuation(
 		return false
 	}
 	// Builder-generated guard continuations sit on the split's horizontal
-	// centerline. This intentionally relies on mxcli's layout contract so a
-	// real branch that returns to a merge below the split is not collapsed into
-	// a guard-style continuation during describe.
-	return dest.GetPosition().Y == split.GetPosition().Y
+	// centerline and use the builder's horizontal split→tail flow. This
+	// intentionally relies on mxcli's layout/anchor contract so a real false
+	// branch whose activities happen to be aligned with the split is not
+	// collapsed into a guard-style continuation during describe.
+	return dest.GetPosition().Y == split.GetPosition().Y &&
+		flow.OriginConnectionIndex == AnchorRight &&
+		flow.DestinationConnectionIndex == AnchorLeft
 }
 
 // findErrorHandlerFlow returns the error handler flow from an activity's outgoing flows.

mdl/executor/cmd_microflows_traverse_test.go

@@ -563,6 +563,9 @@ func TestTraverseFlow_SequentialIfWithoutElseKeepsContinuationOutsideFirstIf(t *
 
 func TestTraverseFlow_GuardBranchWithMultipleActivitiesKeepsContinuationOutsideElse(t *testing.T) {
 	e := newTestExecutor()
+	falseFlow := mkBranchFlow("split", "tail_log", &microflows.ExpressionCase{Expression: "false"})
+	falseFlow.OriginConnectionIndex = AnchorRight
+	falseFlow.DestinationConnectionIndex = AnchorLeft
 
 	activityMap := map[model.ID]microflows.MicroflowObject{
 		mkID("start"): &microflows.StartEvent{BaseMicroflowObject: mkObj("start")},
@@ -585,7 +588,7 @@ func TestTraverseFlow_GuardBranchWithMultipleActivitiesKeepsContinuationOutsideE
 		mkID("start"): {mkFlow("start", "split")},
 		mkID("split"): {
 			mkBranchFlow("split", "then_log", &microflows.ExpressionCase{Expression: "true"}),
-			mkBranchFlow("split", "tail_log", &microflows.ExpressionCase{Expression: "false"}),
+			falseFlow,
 		},
 		mkID("then_log"): {mkFlow("then_log", "then_return")},
 		mkID("tail_log"): {mkFlow("tail_log", "end")},
@@ -607,6 +610,47 @@ func TestTraverseFlow_GuardBranchWithMultipleActivitiesKeepsContinuationOutsideE
 	}
 }
 
+func TestTraverseFlow_TerminalFalseBranchIsNotGuardContinuation(t *testing.T) {
+	e := newTestExecutor()
+
+	activityMap := map[model.ID]microflows.MicroflowObject{
+		mkID("start"): &microflows.StartEvent{BaseMicroflowObject: mkObj("start")},
+		mkID("split"): &microflows.ExclusiveSplit{
+			BaseMicroflowObject: mkObj("split"),
+			SplitCondition:      &microflows.ExpressionSplitCondition{Expression: "$IsAllowed"},
+		},
+		mkID("then_log"): &microflows.ActionActivity{
+			BaseActivity: microflows.BaseActivity{BaseMicroflowObject: mkObj("then_log")},
+			Action:       &microflows.LogMessageAction{LogLevel: "Info", LogNodeName: "'App'", MessageTemplate: &model.Text{Translations: map[string]string{"en_US": "allowed"}}},
+		},
+		mkID("then_return"):  &microflows.EndEvent{BaseMicroflowObject: mkObj("then_return")},
+		mkID("false_log"):    &microflows.ActionActivity{BaseActivity: microflows.BaseActivity{BaseMicroflowObject: mkObj("false_log")}, Action: &microflows.LogMessageAction{LogLevel: "Info", LogNodeName: "'App'", MessageTemplate: &model.Text{Translations: map[string]string{"en_US": "blocked"}}}},
+		mkID("false_return"): &microflows.EndEvent{BaseMicroflowObject: mkObj("false_return")},
+	}
+
+	flowsByOrigin := map[model.ID][]*microflows.SequenceFlow{
+		mkID("start"): {mkFlow("start", "split")},
+		mkID("split"): {
+			mkBranchFlow("split", "then_log", &microflows.ExpressionCase{Expression: "true"}),
+			mkBranchFlow("split", "false_log", &microflows.ExpressionCase{Expression: "false"}),
+		},
+		mkID("then_log"):  {mkFlow("then_log", "then_return")},
+		mkID("false_log"): {mkFlow("false_log", "false_return")},
+	}
+
+	var lines []string
+	visited := make(map[model.ID]bool)
+	e.traverseFlow(mkID("start"), activityMap, flowsByOrigin, nil, visited, nil, nil, &lines, 0, nil, 0, nil)
+
+	out := strings.Join(lines, "\n")
+	if !strings.Contains(out, "\nelse\n") {
+		t.Fatalf("terminal false branch must stay inside an explicit ELSE:\n%s", out)
+	}
+	if strings.Index(out, "blocked") < strings.Index(out, "else") {
+		t.Fatalf("false branch body was emitted outside ELSE:\n%s", out)
+	}
+}
+
 func TestTraverseFlow_NestedTerminalGuardBranchSuppressesEmptyOuterElse(t *testing.T) {
 	e := newTestExecutor()