feat: IMAP sync incremental + Account Setup Wizard + robust FETCH parser

- ImapSynchronizer::syncFolder(): detecta eliminados (UIDs locales no en servidor), fetch nuevos (sinceUid), actualiza flags (FLAGS batch)
- fetchAllUids(): SELECT + SEARCH ALL para lista completa UIDs servidor
- parseAndUpdateFlags(): FETCH FLAGS en lotes 100, update DB si cambió read/flagged
- AccountSetupDialog: integra ConnectionWizard para IMAP/POP3 con test de conexión real
- IMAP FETCH parser robusto: logging respuesta servidor + fallback UID-by-UID
- Fix: FETCH failed logging muestra first/last UID + respuesta truncada

src/ui/readerview.cpp

@@ -1,5 +1,8 @@
 #include "ui/readerview.h"
 #include <QFont>
+#include <QDesktopServices>
+#include <QUrl>
+#include "db/dao/mailitemdao.h"
 
 ReaderView::ReaderView(QWidget *parent) : QWidget(parent) {
     setupUI();
@@ -55,8 +58,19 @@ void ReaderView::setupUI() {
     m_bodyViewer->setOpenExternalLinks(true);
     m_bodyViewer->setFrameStyle(QFrame::NoFrame);
 
+    m_attachmentList = new QListWidget();
+    m_attachmentList->setVisible(false);
+    m_attachmentList->setMaximumHeight(110);
+    m_attachmentList->setToolTip(tr("Double-click an attachment to open it"));
+    connect(m_attachmentList, &QListWidget::itemDoubleClicked, this,
+            [](QListWidgetItem *listItem) {
+                const QString path = listItem->data(Qt::UserRole).toString();
+                if (!path.isEmpty()) QDesktopServices::openUrl(QUrl::fromLocalFile(path));
+            });
+
     mainLayout->addWidget(headerWidget);
     mainLayout->addLayout(actionsLayout);
+    mainLayout->addWidget(m_attachmentList);
     mainLayout->addWidget(m_bodyViewer);
 
     // Connections
@@ -72,6 +86,8 @@ void ReaderView::setMailItem(const MailItem* item) {
         m_subjectLabel->setText("No mail selected");
         m_fromLabel->setText("From: ");
         m_dateLabel->setText("Date: ");
+        m_attachmentList->clear();
+        m_attachmentList->setVisible(false);
         m_bodyViewer->setHtml("<i>Please select a message to read</i>");
         return;
     }
@@ -79,5 +95,13 @@ void ReaderView::setMailItem(const MailItem* item) {
     m_subjectLabel->setText(item->subject());
     m_fromLabel->setText(QString("From: %1").arg(item->sender()));
     m_dateLabel->setText(QString("Date: %1").arg(item->date().toString("ddd, d MMM yyyy hh:mm")));
+    m_attachmentList->clear();
+    const QVector<StoredAttachmentRecord> attachments = MailItemDao::attachmentsForMail(item->id());
+    for (const StoredAttachmentRecord &attachment : attachments) {
+        auto *listItem = new QListWidgetItem(attachment.fileName, m_attachmentList);
+        listItem->setData(Qt::UserRole, attachment.storedPath);
+        listItem->setToolTip(attachment.storedPath);
+    }
+    m_attachmentList->setVisible(!attachments.isEmpty());
     m_bodyViewer->setHtml(item->bodyHtml());
-}
+}