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- Remove legacy initStatusFilter() (superseded by TDS v1.2 sidebar filters)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>

assets/css/ticket.css

@@ -85,11 +85,16 @@ body.edit-mode .editable-metadata {
   border: 1px solid rgba(0, 255, 65, 0.2);
 }
 .comment-reply {
+  /* depth-1 default; .thread-depth-N overrides for deeper nesting */
   margin-left: 1.5rem;
   border-color: rgba(0, 255, 65, 0.12);
 }
-.thread-depth-2 { margin-left: 3rem; }
-.thread-depth-3 { margin-left: 4.5rem; }
+/* Explicit depth overrides using combined selectors — higher specificity prevents
+   cascade order from determining winner when both classes are present */
+.comment.thread-depth-2,
+.comment-reply.thread-depth-2 { margin-left: 3rem; }
+.comment.thread-depth-3,
+.comment-reply.thread-depth-3 { margin-left: 4.5rem; }
 
 .thread-line {
   position: absolute;