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>