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

src/ui/maillistview.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <QWidget>
+#include <QTableView>
+#include <QHeaderView>
+#include <QSortFilterProxyModel>
+#include <QVBoxLayout>
+#include <QPushButton>
+#include <QLabel>
+
+#include "ui/models/EmailListModel.h"
+
+class MailListView : public QWidget {
+    Q_OBJECT
+
+public:
+    explicit MailListView(QWidget *parent = nullptr);
+    ~MailListView() override = default;
+
+    void setModel(EmailListModel *model);
+
+signals:
+    void emailSelected(int mailId);
+    void composeRequested();
+
+private slots:
+    void onRowSelected(const QModelIndex &index);
+
+private:
+    void setupUI();
+
+    QTableView *m_tableView;
+    QSortFilterProxyModel *m_proxyModel;
+    QPushButton *m_composeButton;
+};