Fix webmail account switcher and improve error handling

- Fix apiSSO() resetting selected account to first one on every call,
  now preserves previously selected account if still valid
- Fix webmail.conf ownership to use cyberpanel:cyberpanel (Django runs
  as cyberpanel user, not nobody)
- Add error notifications when SSO or folder loading fails

install/installCyberPanel.py

@@ -740,7 +740,7 @@ module cyberpanel_ols {
             with open('/etc/cyberpanel/webmail.conf', 'w') as f:
                 json_module.dump(webmail_conf, f)
             os.chmod('/etc/cyberpanel/webmail.conf', 0o600)
-            subprocess.call(['chown', 'nobody:nobody', '/etc/cyberpanel/webmail.conf'])
+            subprocess.call(['chown', 'cyberpanel:cyberpanel', '/etc/cyberpanel/webmail.conf'])
 
             InstallCyberPanel.stdOut("Webmail master user setup complete!", 1)
             return 1

plogical/upgrade.py

@@ -2846,7 +2846,7 @@ CREATE TABLE `websiteFunctions_backupsv2` (`id` integer AUTO_INCREMENT NOT NULL
             with open('/etc/cyberpanel/webmail.conf', 'w') as f:
                 json.dump(webmail_conf, f)
             os.chmod('/etc/cyberpanel/webmail.conf', 0o600)
-            subprocess.call(['chown', 'nobody:nobody', '/etc/cyberpanel/webmail.conf'])
+            subprocess.call(['chown', 'cyberpanel:cyberpanel', '/etc/cyberpanel/webmail.conf'])
 
             # Patch dovecot.conf if master user config not present
             dovecot_conf_path = '/etc/dovecot/dovecot.conf'

webmail/static/webmail/webmail.js

@@ -171,6 +171,8 @@ app.controller('webmailCtrl', ['$scope', '$http', '$sce', '$timeout', function($
                 $scope.switchEmail = data.email;
                 $scope.loadFolders();
                 $scope.loadSettings();
+            } else {
+                notify(data.error_message || 'No email accounts found. Create an email account first or use the standalone login.', 'error');
             }
         });
     };
@@ -199,6 +201,8 @@ app.controller('webmailCtrl', ['$scope', '$http', '$sce', '$timeout', function($
             if (data.status === 1) {
                 $scope.folders = data.folders;
                 $scope.loadMessages();
+            } else {
+                notify(data.error_message || 'Failed to load folders.', 'error');
             }
         });
     };

webmail/webmailManager.py

@@ -184,9 +184,12 @@ class WebmailManager:
         accounts = self._get_managed_accounts()
         if not accounts:
             return self._error('No email accounts found for your user.')
-        email = accounts[0]
-        self.request.session['webmail_email'] = email
-        return self._success({'email': email, 'accounts': accounts})
+        # Preserve previously selected account if still valid
+        current = self.request.session.get('webmail_email')
+        if not current or current not in accounts:
+            current = accounts[0]
+        self.request.session['webmail_email'] = current
+        return self._success({'email': current, 'accounts': accounts})
 
     def apiListAccounts(self):
         accounts = self._get_managed_accounts()