feat: add import support and unit tests for provider resources

terraform/provider/internal/resources/import_helpers.go

@@ -0,0 +1,16 @@
+package resources
+
+import (
+	"fmt"
+	"strings"
+)
+
+// parseImportID разбирает импорт в формате namespace/name.
+func parseImportID(importID string) (string, string, error) {
+	parts := strings.Split(importID, "/")
+	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+		return "", "", fmt.Errorf("invalid import id %q, expected format namespace/name", importID)
+	}
+
+	return parts[0], parts[1], nil
+}