feat: SLA live timer, notification bell, lt-toggle MD, right drawer, kanban drag-drop

- TicketView: SLA banner now shows live HH:MM:SS elapsed + countdown via JS setInterval
  (previously showed static hours from PHP)
- TicketView: Markdown toggles in comment form replaced with lt-toggle switches
- layout_header: In-app notification bell (🔔) with dropdown panel for all users
- layout_footer: Notification JS — polls /api/notifications.php every 60s, badge count,
  mark-all-read, panel open/close with Escape/outside-click
- api/notifications.php (new): Returns assign/comment/status-change events from audit_log
  for current user's tickets and watched tickets; mark-read via user_preferences
- DashboardView: Ticket preview right drawer — Ctrl+click title or ⊙ peek button
  opens lt-drawer-right with ticket summary extracted from table row DOM
- DashboardView: lt.sortable wired on all 4 kanban columns (group='kanban')
  Cross-column drag = status change via POST /api/update_ticket.php with optimistic UI

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

views/layout_footer.php

@@ -172,6 +172,84 @@
       });
     }
 
+    // ── Notification Bell ─────────────────────────────────────────────
+<?php if (!empty($GLOBALS['currentUser'])): ?>
+    (function() {
+      var bell     = document.getElementById('lt-notif-bell');
+      var panel    = document.getElementById('lt-notif-panel');
+      var list     = document.getElementById('lt-notif-list');
+      var clearBtn = document.getElementById('lt-notif-clear-btn');
+      var wrapEl   = document.getElementById('lt-notif-wrap');
+      if (!bell || !panel) return;
+
+      var _open = false;
+
+      function fmtTime(dateStr) {
+        var d = new Date(dateStr);
+        var diff = Math.floor((Date.now() - d) / 1000);
+        if (diff < 60)   return diff + 's ago';
+        if (diff < 3600) return Math.floor(diff / 60) + 'm ago';
+        if (diff < 86400)return Math.floor(diff / 3600) + 'h ago';
+        return Math.floor(diff / 86400) + 'd ago';
+      }
+
+      function esc(s) { return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;'); }
+
+      function renderNotifications(data) {
+        lt.notif.set(bell, data.unread_count || 0);
+        if (!data.notifications || !data.notifications.length) {
+          list.innerHTML = '<div style="padding:1rem;font-size:0.75rem;color:var(--text-muted);text-align:center">No recent notifications</div>';
+          return;
+        }
+        list.innerHTML = data.notifications.map(function(n) {
+          return '<div class="lt-notif-item' + (n.is_read ? '' : ' lt-notif-item--unread') +
+            '" tabindex="0" role="link" data-url="' + esc(n.url) + '">' +
+            '<div class="lt-notif-dot' + (n.is_read ? ' lt-notif-dot--read' : '') + '"></div>' +
+            '<div class="lt-notif-item-body">' +
+              '<div class="lt-notif-item-title">' + esc(n.title) + '</div>' +
+              '<div class="lt-notif-item-time">' + fmtTime(n.created_at) + '</div>' +
+            '</div></div>';
+        }).join('');
+        list.querySelectorAll('.lt-notif-item').forEach(function(item) {
+          function go() { if (item.dataset.url) window.location.href = item.dataset.url; }
+          item.addEventListener('click', go);
+          item.addEventListener('keydown', function(e) { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); go(); } });
+        });
+      }
+
+      function loadNotifications() {
+        fetch('/api/notifications.php', { credentials: 'same-origin' })
+          .then(function(r) { return r.json(); })
+          .then(renderNotifications)
+          .catch(function() {
+            list.innerHTML = '<div style="padding:0.75rem;font-size:0.75rem;color:var(--text-muted);text-align:center">Could not load</div>';
+          });
+      }
+
+      function openPanel()  { _open = true;  panel.removeAttribute('aria-hidden'); bell.setAttribute('aria-expanded','true');  loadNotifications(); }
+      function closePanel() { _open = false; panel.setAttribute('aria-hidden','true'); bell.setAttribute('aria-expanded','false'); }
+
+      bell.addEventListener('click', function(e) { e.stopPropagation(); _open ? closePanel() : openPanel(); });
+
+      if (clearBtn) {
+        clearBtn.addEventListener('click', function() {
+          fetch('/api/notifications.php', {
+            method: 'POST', credentials: 'same-origin',
+            headers: { 'Content-Type': 'application/json', 'X-CSRF-Token': window.CSRF_TOKEN || '' },
+            body: JSON.stringify({ action: 'mark_read' })
+          }).then(loadNotifications);
+        });
+      }
+
+      document.addEventListener('click', function(e) { if (_open && wrapEl && !wrapEl.contains(e.target)) closePanel(); });
+      document.addEventListener('keydown', function(e) { if (e.key === 'Escape' && _open) closePanel(); });
+
+      // Initial badge count + poll every 60s
+      loadNotifications();
+      setInterval(loadNotifications, 60000);
+    })();
+<?php endif ?>
+
     // Footer hint bar actions (keyboard help + settings — work on all pages)
     document.addEventListener('click', function(e) {
       var btn = e.target.closest('[data-action]');