Add command palette (Ctrl+K / Cmd+K) globally

Adds lt-cmd-overlay HTML to layout_header.php and initializes
lt.cmdPalette with commands for: navigation (Dashboard, New Ticket),
filters (My Tickets, Unassigned, P1 Critical), admin pages (if admin),
and recent tickets (last 5 viewed, stored in localStorage).

TicketView.php records each viewed ticket ID to localStorage under
lt_recent_tickets so the command palette can surface them as Recent.

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

views/TicketView.php

@@ -120,6 +120,16 @@ window.ticketData = {
 };
 window.ticketData.id = window.ticketData.ticket_id;
 if (window.lt) lt.keys.initDefaults();
+// Track recently viewed tickets for command palette
+(function() {
+  try {
+    var tid = String(window.ticketData.ticket_id);
+    var key = 'lt_recent_tickets';
+    var r = JSON.parse(localStorage.getItem(key) || '[]');
+    r = [tid].concat(r.filter(function(x){ return x !== tid; })).slice(0, 5);
+    localStorage.setItem(key, JSON.stringify(r));
+  } catch(_) {}
+})();
 JS;
 
 include __DIR__ . '/layout_header.php';