Fix build: synchronize Request API, fix GmailSynchronizer, and migrate UI to Qt6 Widgets

include/accountservice.h

@@ -0,0 +1,24 @@
+// accountservice.h
+#ifndef ACCOUNTSERVICE_H
+#define ACCOUNTSERVICE_H
+
+#include "authenticator.h"
+#include "eventbus.h"
+#include <QString>
+
+class AccountService {
+public:
+    AccountService(EventBus* bus);
+
+    // Interface for managing user accounts
+    bool registerAccount(const QString& type, const QString& identifier, const QString& credentials);
+    bool syncAccount(const QString& accountId, const QString& type);
+
+private:
+    EventBus* m_eventBus;
+    // Placeholder for DAO layer (Data Access Objects)
+    // In a full implementation, these would handle DB/file operations.
+    bool saveAccountToDB(const QString& accountId, const QString& type, const QString& details);
+};
+
+#endif // ACCOUNTSERVICE_H