fix: Cache busting and visibility group editing UI

- Add cache busting query params to JS/CSS files (v=20260123)
- Add visibility group selection UI for editing existing tickets
- Add toggleVisibilityGroupsEdit() and getSelectedVisibilityGroups() functions
- Fix visibility data being saved when editing tickets
- Pass $conn to views for UserModel access

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

assets/js/ticket.js

@@ -5,6 +5,25 @@ function escapeHtml(text) {
     return div.innerHTML;
 }
 
+/**
+ * Toggle visibility groups field based on visibility selection
+ */
+function toggleVisibilityGroupsEdit() {
+    const visibility = document.getElementById('visibilitySelect')?.value;
+    const groupsField = document.getElementById('visibilityGroupsField');
+    if (groupsField) {
+        groupsField.style.display = visibility === 'internal' ? 'block' : 'none';
+    }
+}
+
+/**
+ * Get selected visibility groups
+ */
+function getSelectedVisibilityGroups() {
+    const checkboxes = document.querySelectorAll('.visibility-group-checkbox:checked');
+    return Array.from(checkboxes).map(cb => cb.value);
+}
+
 function saveTicket() {
     const editables = document.querySelectorAll('.editable');
     const data = {};
@@ -34,9 +53,18 @@ function saveTicket() {
         }
     });
 
+    // Get visibility settings
+    const visibilitySelect = document.getElementById('visibilitySelect');
+    if (visibilitySelect) {
+        data.visibility = visibilitySelect.value;
+        if (data.visibility === 'internal') {
+            data.visibility_groups = getSelectedVisibilityGroups();
+        }
+    }
+
     // Use the correct API path
     const apiUrl = '/api/update_ticket.php';
-    
+
     fetch(apiUrl, {
         method: 'POST',
         headers: {