fix(cabana): dereference nullable pointer scalars in ML host hydration

- hostScalarString walks pointers via reflect; nil at any depth is ""
- string kinds return raw text, byte slices decode, other kinds format the dereferenced value
- Postgres round-trip regression for an mltext field on a *string column

modules/cabana/field_ml.go

@@ -3,6 +3,7 @@ package cabana
 import (
 	"context"
 	"fmt"
+	"reflect"
 
 	"gorm.io/gorm"
 )
@@ -217,16 +218,29 @@ func hydrateMLRecord(ctx context.Context, tx *gorm.DB, cc *CompiledController, w
 	return nil
 }
 
+// hostScalarString renders a projected host column as the default-locale text.
+// Nullable pointer columns (*string, *int, **string, ...) are dereferenced at
+// any depth and a nil pointer becomes the empty string, so neither "<nil>" nor
+// a pointer address reaches the admin form. String kinds return their raw text
+// (bypassing any String method), byte slices are decoded as text and every
+// other kind is formatted from the dereferenced value.
 func hostScalarString(v any) string {
 	if v == nil {
 		return ""
 	}
-	switch t := v.(type) {
-	case string:
-		return t
-	case []byte:
-		return string(t)
+	rv := reflect.ValueOf(v)
+	for rv.Kind() == reflect.Pointer {
+		if rv.IsNil() {
+			return ""
+		}
+		rv = rv.Elem()
+	}
+	switch {
+	case rv.Kind() == reflect.String:
+		return rv.String()
+	case rv.Kind() == reflect.Slice && rv.Type().Elem().Kind() == reflect.Uint8:
+		return string(rv.Bytes())
 	default:
-		return fmt.Sprint(t)
+		return fmt.Sprint(rv.Interface())
 	}
 }