chore: prepare v1.0.0 release

lib/guards.ts

@@ -0,0 +1,7 @@
+export function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null
+}
+
+export function getErrorMessage(error: unknown, fallback = 'Erreur inconnue') {
+  return error instanceof Error ? error.message : fallback
+}