fix: default detected annotation and check CreateAndCheckout error

- Add default case in `formatNode` so detected nodes with any
  confidence level (including zero value) always show "(detected)"
- Check `CreateAndCheckout` error in `TestRevListCount`

Author: boneskull

internal/git/git_test.go

@@ -796,7 +796,9 @@ func TestRevListCount(t *testing.T) {
 	trunk, _ := g.CurrentBranch()
 
 	// Create feature branch with 3 commits
-	g.CreateAndCheckout("feature")
+	if err := g.CreateAndCheckout("feature"); err != nil {
+		t.Fatalf("CreateAndCheckout(feature): %v", err)
+	}
 	for i := range 3 {
 		fname := filepath.Join(dir, fmt.Sprintf("file%d.txt", i))
 		if err := os.WriteFile(fname, fmt.Appendf(nil, "content%d", i), 0644); err != nil {

internal/tree/tree.go

@@ -181,12 +181,12 @@ func formatNode(sb *strings.Builder, node *Node, prefix string, isLast bool, opt
 	detectedInfo := ""
 	if node.Detected {
 		switch node.Confidence {
-		case ConfidenceMedium:
-			detectedInfo = " (detected)"
-		case ConfidenceAmbiguous:
-			detectedInfo = " (detected, ambiguous)"
 		case ConfidenceHigh:
 			detectedInfo = " (detected, via PR)"
+		case ConfidenceAmbiguous:
+			detectedInfo = " (detected, ambiguous)"
+		default:
+			detectedInfo = " (detected)"
 		}
 		if opts.Style != nil {
 			detectedInfo = opts.Style.Muted(detectedInfo)