Delete-FTP-User Button und Fix für sudoers-Pfad

- Plugin: Neuer "Delete FTP User" Button im FTP-User-Bereich
  - Mit Bestätigungsdialog
  - Löscht nur FTP-Account + Bind-Mounts, System-User bleibt unberührt
- Helper-Script: neues 'deluser' Kommando
- sudoers-Fix: tee für /etc/pure-ftpd/* (statt nur conf/*) —
  cmd_passwd muss nach /etc/pure-ftpd/pureftpd.passwd schreiben können,
  das war vorher nicht erlaubt und führte zu 'Failed to create FTP user'
  beim Anlegen weiterer User

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

kf6/src/ftpshareplugin.cpp

@@ -141,17 +141,20 @@ FtpSharePlugin::FtpSharePlugin(QObject *parent, const QVariantList &args)
     usersLayout->addWidget(scrollArea);
     mainLayout->addWidget(usersGroup);
 
-    // Change password section
-    auto *pwGroup = new QGroupBox(i18n("FTP Password"));
+    // FTP user management section
+    auto *pwGroup = new QGroupBox(i18n("FTP User"));
     auto *pwLayout = new QHBoxLayout(pwGroup);
     m_pwUserCombo = new QComboBox();
     m_pwUserCombo->addItems(users);
     auto *pwButton = new QPushButton(i18n("Change Password..."));
+    auto *deleteButton = new QPushButton(i18n("Delete FTP User"));
     pwLayout->addWidget(m_pwUserCombo);
     pwLayout->addWidget(pwButton);
+    pwLayout->addWidget(deleteButton);
     mainLayout->addWidget(pwGroup);
 
     connect(pwButton, &QPushButton::clicked, this, &FtpSharePlugin::onChangePassword);
+    connect(deleteButton, &QPushButton::clicked, this, &FtpSharePlugin::onDeleteFtpUser);
 
     // Server configuration section
     auto *serverGroup = new QGroupBox(i18n("Server Configuration"));
@@ -483,4 +486,44 @@ void FtpSharePlugin::onChangePassword()
     }
 }
 
+void FtpSharePlugin::onDeleteFtpUser()
+{
+    const QString username = m_pwUserCombo->currentText();
+    if (username.isEmpty())
+        return;
+
+    if (!ftpUserExists(username)) {
+        QMessageBox::information(m_page,
+            i18n("Delete FTP User"),
+            i18n("User '%1' has no FTP account.", username));
+        return;
+    }
+
+    const auto result = QMessageBox::question(m_page,
+        i18n("Delete FTP User"),
+        i18n("Really delete FTP account for '%1'?\n\n"
+             "The system user stays untouched. Only the FTP login and\n"
+             "this user's bind-mounts in the FTP root will be removed.", username),
+        QMessageBox::Yes | QMessageBox::No,
+        QMessageBox::No);
+
+    if (result != QMessageBox::Yes)
+        return;
+
+    QProcess proc;
+    proc.start(QStringLiteral("dolphin-ftp-share"),
+               {QStringLiteral("deluser"), username});
+    proc.waitForFinished(10000);
+
+    if (proc.exitCode() == 0) {
+        QMessageBox::information(m_page,
+            i18n("Delete FTP User"),
+            i18n("FTP user '%1' deleted.", username));
+    } else {
+        QMessageBox::warning(m_page,
+            i18n("Delete FTP User"),
+            i18n("Failed to delete FTP user '%1'.", username));
+    }
+}
+
 #include "ftpshareplugin.moc"

kf6/src/ftpshareplugin.h

@@ -27,6 +27,7 @@ private:
     void loadServerConfig();
     void onShareToggled(bool checked);
     void onChangePassword();
+    void onDeleteFtpUser();
     void onApplyServerConfig();
     void onModeChanged();