fix FAQ shortcode: use ~~~ separator, function-style split, trim whitespace

Hugo strips --- (interprets as thematic break) from shortcode .Inner content.
Switch to ~~~ separator. Also fix split syntax (function-style instead of pipe)
and add trim to handle whitespace around items.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

layouts/shortcodes/faq.html

@@ -1,8 +1,11 @@
 {{/* FAQ shortcode — renders as expandable details + outputs FAQPage schema for AI search */}}
-{{ $items := .Inner | split "---" }}
+{{ $raw := .Inner }}
+{{ $items := split $raw "~~~" }}
 <div class="faq-section">
 {{ range $items }}
-{{ $parts := . | split "?" }}
+{{ $trimmed := trim . "\n\r\t " }}
+{{ if $trimmed }}
+{{ $parts := split $trimmed "?" }}
 {{ if gt (len $parts) 1 }}
 <details class="faq-item" style="margin-bottom: 0.75rem; border: 1px solid #e2e8f0; border-radius: 8px; padding: 0;">
   <summary style="padding: 0.75rem 1rem; cursor: pointer; font-weight: 600; list-style: none;">{{ index $parts 0 | markdownify }}?</summary>
@@ -10,4 +13,5 @@
 </details>
 {{ end }}
 {{ end }}
+{{ end }}
 </div>