feat: make password optional for session restoration

src/client.ts

@@ -71,7 +71,7 @@ export class TrytonClient {
 
         this.database = database;
         this.username = username;
-        this.password = password;
+        this.password = password || ""; // Empty string if not provided
         this.port = port;
         this.language = language;
         this.options = options;

types.ts

@@ -16,7 +16,7 @@ export interface TrytonClientConfig {
     hostname: string;
     database: string;
     username: string;
-    password: string;
+    password?: string; // Optional - no necesario para restaurar sesión
     port?: number;
     language?: string;
     options?: TrytonClientOptions;