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

include/concreterequests.h

@@ -0,0 +1,27 @@
+// concreterequests.h
+#ifndef CONCRETEREQUESTS_H
+#define CONCRETEREQUESTS_H
+
+#include "request.h"
+#include <QString>
+
+class Concreterequests {
+public:
+    // Interface for defining specific request types (e.g., IMAP GET, SMTP AUTH)
+    virtual Request* createRequest(const QString& type, const QString& target) = 0;
+    virtual ~Concreterequests() = default;
+};
+
+class ImapRequest : public Concreterequests {
+public:
+    ImapRequest(Request* req);
+    Request* createRequest(const QString& type, const QString& target) override;
+};
+
+class SmtpRequest : public Concreterequests {
+public:
+    SmtpRequest(Request* req);
+    Request* createRequest(const QString& type, const QString& target) override;
+};
+
+#endif // CONCRETEREQUESTS_H