fix: CSS nesting conflict, dashboard.js dead code removal, admin view escaping

CSS:
- ticket.css: use combined .comment.thread-depth-N selectors to resolve the
  margin-left conflict between .comment-reply and .thread-depth-N classes

dashboard.js:
- Remove legacy initStatusFilter() (superseded by TDS v1.2 sidebar filters)
- Remove initTableSorting() call (client-side sort conflicts with server ?sort=)
- Remove quickSave() + saveTicket() (old hamburger-menu ticket page functions)
- Remove global loadTemplate() (duplicate of IIFE-scoped version in CreateTicketView)
- Remove generateSkeletonRows/Comments/Stats helpers (never called, used
  unregistered CSS class names like .skeleton-row-tr)
- Remove "force dark mode" lines that overrode the user theme preference
- Fix non-TDS CSS classes in modal templates: text-center → style, text-green →
  lt-text-cyan, mb-half → lt-mb-xs, modal-warning-text → lt-text-danger

Admin views:
- RecurringTicketsView: replace innerHTML += loop with createElement/appendChild
  (avoids serial DOM re-parsing on each iteration)
- AuditLogView: add htmlspecialchars() to action_type option values (consistency)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

views/admin/RecurringTicketsView.php

@@ -204,12 +204,18 @@ function updateScheduleOptions() {
     } else if (type === 'weekly') {
         dayRow.classList.remove('is-hidden');
         ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'].forEach(function (day, i) {
-            daySelect.innerHTML += '<option value="' + (i + 1) + '">' + day + '</option>';
+            var opt = document.createElement('option');
+            opt.value = String(i + 1);
+            opt.textContent = day;
+            daySelect.appendChild(opt);
         });
     } else if (type === 'monthly') {
         dayRow.classList.remove('is-hidden');
         for (var i = 1; i <= 28; i++) {
-            daySelect.innerHTML += '<option value="' + i + '">Day ' + i + '</option>';
+            var opt = document.createElement('option');
+            opt.value = String(i);
+            opt.textContent = 'Day ' + i;
+            daySelect.appendChild(opt);
         }
     }
 }