Fix CSP-blocked chart scripts, undefined CSS classes, and double-firing click handlers

- Add nonce to charts and ticket-preview drawer inline <script> blocks in
  DashboardView.php (both were CSP-blocked — charts never rendered)
- Add .lt-modal-xs (280px) to base.css — used by quickStatus/quickAssign
  modals but was undefined, causing them to use full modal width
- Fix showConfirmModal in utils.js: class="text-center" → "lt-text-center"
  (undefined class); escape newlines as <br> so multi-line messages render
- Remove duplicate click-handler cases from DashboardView.php inline script
  that were already handled by dashboard.js, preventing double-firing
  (export-tickets, open-settings, remove-filter, etc. were all called twice)
- Fix manual-refresh action to use lt.autoRefresh.now() instead of bare
  window.location.reload() so modal/focus guards are respected

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

assets/css/base.css

@@ -1317,7 +1317,8 @@ select option:checked {
 .lt-modal-close:active { color: var(--accent-red); opacity: 0.7; }
 .lt-modal-close:focus-visible { outline: 2px solid var(--accent-cyan); outline-offset: 2px; border-radius: 2px; }
 
-/* Modal size modifier */
+/* Modal size modifiers */
+.lt-modal-xs { width: min(280px, 92vw); }
 .lt-modal-sm { width: min(360px, 92vw); }
 
 /* Modal header danger variant */