Fix views/controllers/router: command palette, create form, admin views

- Consolidate the duplicated command palette to a single overlay + init in
  the footer; fix New Ticket to route to /ticket/create (was a 404 /create);
  keep the CSP nonce and all commands
- TicketController create(): trim title, require a non-empty description,
  and honor the posted status (validated against the canonical list) instead
  of silently discarding it
- UserActivityView: 'Active Users' counts only users active in the selected
  range, not every registered user
- layout_footer/DashboardView: local esc() now escapes quotes so values used
  in HTML attributes can't break out
- TicketView: comments tab badge shows the true total, not just page one
- layout_header: gate the 'View activity log' link behind the admin flag
- index.php: validate /admin/user-activity date params; anchor the legacy
  /ticket.php route; align the audit action-type whitelist with the dropdown
- ApiKeysView: correct the external API sample to /create_ticket_api.php

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

views/DashboardView.php

@@ -1317,7 +1317,7 @@ if (advForm) advForm.addEventListener('submit', function(e) {
   var pLabels = { '1':'P1 — Critical', '2':'P2 — High', '3':'P3 — Medium', '4':'P4 — Low', '5':'P5 — Minimal' };
   var dotClass = { 'Open':'lt-dot-up', 'In Progress':'lt-dot-warn', 'Pending':'lt-dot--orange', 'Closed':'lt-dot-idle' };
 
-  function esc(s) { return String(s||'').replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;'); }
+  function esc(s) { return String(s||'').replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;').replace(/'/g,'&#39;'); }
 
   function fmtAge(dateStr) {
     var d = new Date(dateStr);