Install/upgrade and UI updates: monolithic install, SnappyMail, firewall, to-do docs

- Install: monolithic install script, venvsetup_modules and venvsetup_monolithic,
  install_modules (parse_main, menus, actions, etc.), remove legacy email-configs
  and php-configs from repo, add install/snappymail and Rainloop->SnappyMail
  migration script
- CyberPanel: urls.py, cyberpanel.sh, cyberpanel_upgrade_monolithic.sh tweaks
- Firewall: firewall.js and firewall.html updates
- plogical: mailUtilities.py, upgrade.py; upgrade_modules 10_post_tweak.sh
- pluginHolder: deploy-plugins-template.sh
- to-do: docs (git conflicts, HTTP 500 recovery, phpMyAdmin, plugins, SnappyMail
  rename, install/upgrade OS support, security whitelist, etc.)
- upgrade_modules: 02_checks_part1/part2.txt

firewall/static/firewall/firewall.js

@@ -31,6 +31,8 @@ app.controller('firewallController', function ($scope, $http, $timeout) {
     $scope.couldNotConnect = true;
     $scope.rulesDetails = false;
 
+    // Initialize rules array - prevents "Cannot read 'length' of undefined" when template evaluates rules.length before API loads
+    $scope.rules = [];
     // Banned IPs variables – tab from hash so we stay on /firewall/ (avoids 404 on servers without /firewall/firewall-rules/)
     function tabFromHash() {
         var h = (window.location.hash || '').replace(/^#/, '');

firewall/templates/firewall/firewall.html

@@ -1293,7 +1293,7 @@
         <!-- Rules Table -->
         <div ng-hide="rulesDetails" class="rules-table-section">
             <div class="table-responsive">
-                <table class="rules-table" ng-if="rules.length > 0">
+                <table class="rules-table" ng-if="rules && rules.length > 0">
                 <thead>
                     <tr>
                         <th>{% trans "ID" %}</th>
@@ -1361,7 +1361,7 @@
             </div>
             
             <!-- Empty State -->
-            <div ng-if="rules.length == 0" class="empty-state">
+            <div ng-if="!rules || rules.length == 0" class="empty-state">
                 <i class="fas fa-shield-alt empty-icon"></i>
                 <h3 class="empty-title">{% trans "No Firewall Rules" %}</h3>
                 <p class="empty-text">{% trans "Add your first firewall rule to control network access to your server." %}</p>