Implement RBAC migration and role management enhancements

- Added AJAX functionality to fetch role permissions for copying.
- Introduced system role management with permission checks for updates.
- Implemented role deletion with confirmation modal and backend handling.
- Enhanced user role assignment migration scripts to transition from legacy profiles to RBAC.
- Created SQL migration scripts for user roles and permissions mapping.
- Updated user interface to support new role management features including copy permissions and system role indicators.

style/admin.css

@@ -591,6 +591,8 @@ main .content-block-wrapper .content-block {
   width: 100%;
   margin: 0 10px;
   border-radius: 3px;
+  max-height: 300px;
+  overflow-y: auto;
 }
 
 main .content-block-wrapper .content-block:first-child {
@@ -3140,6 +3142,61 @@ main .content-block .button-container {
     border-top: 1px solid #eee;
 }
 
+/* Generic Modal Styles */
+.modal {
+    display: none;
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background: rgba(0, 0, 0, 0.5);
+    z-index: 1000;
+    align-items: center;
+    justify-content: center;
+}
+
+.modal .modal-content {
+    background: white;
+    border-radius: 12px;
+    max-width: 500px;
+    width: 90%;
+    max-height: 90vh;
+    overflow-y: auto;
+    margin: 20px;
+    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
+}
+
+.modal .modal-header {
+    padding: 20px 25px;
+    border-bottom: 1px solid #e0e0e0;
+}
+
+.modal .modal-header h3 {
+    margin: 0;
+    color: #333;
+    display: flex;
+    align-items: center;
+    gap: 10px;
+}
+
+.modal .modal-body {
+    padding: 25px;
+}
+
+.modal .modal-body p {
+    margin: 0 0 10px 0;
+}
+
+.btn.danger {
+    background-color: #e74c3c;
+    color: white;
+}
+
+.btn.danger:hover {
+    background-color: #c0392b;
+}
+
 /* Registration Modal Styles */
 
 .reg-modal {