fix(marketing): A-2.7b WCAG 2.2 AA polish + JSON-LD test hardening

- Drop role="region" from FAQ panels (had no accessible name — axe-core
  violation; disclosure pattern with button + aria-controls + aria-expanded
  is sufficient per WAI-APG accordion guidance)
- Add focus-visible:outline-2 outline-brand-b1 outline-offset-2 to FAQ
  buttons (WCAG 2.2 AA 2.4.7 Focus Not Obscured + 2.4.11 Focus Appearance —
  Safari default focus indicator is unreliable)
- Sweep pre-existing text-white/50 on Hero social proof microcopy → /70
  (branch-wide WCAG floor; recurring landmine flagged at A-2.7a review)
- Strengthen test_faq_jsonld_schema_present to json.loads() the extracted
  block and validate the FAQPage schema shape (regression guard for future
  content edits with unescaped backslashes/quotes)

templates/marketing/landing.html

@@ -51,7 +51,7 @@
       </div>
 
       {# Social proof microcopy — defensible: refers to pre-launch waitlist + factual ordres pros count #}
-      <p class="mt-8 text-sm text-white/50 animate-tc-fade-in-up" style="animation-delay: 400ms; animation-fill-mode: backwards;">
+      <p class="mt-8 text-sm text-white/70 animate-tc-fade-in-up" style="animation-delay: 400ms; animation-fill-mode: backwards;">
         <span class="inline-flex items-center gap-1.5">
           <svg width="14" height="14" viewBox="0 0 20 20" fill="currentColor" class="text-brand-b3" aria-hidden="true">
             <path d="M10 2L3 5v5.5c0 4.04 2.84 7.85 7 8.5 4.16-.65 7-4.46 7-8.5V5l-7-3z"/>
@@ -484,7 +484,7 @@
       <div x-data="{ open: false }" class="py-2" role="listitem">
         <h3>
           <button type="button"
-                  class="w-full flex items-center justify-between gap-4 py-4 text-left hover:bg-brand-bg/50 transition-colors rounded-md px-2"
+                  class="w-full flex items-center justify-between gap-4 py-4 text-left hover:bg-brand-bg/50 transition-colors rounded-md px-2 focus-visible:outline-2 focus-visible:outline-brand-b1 focus-visible:outline-offset-2"
                   @click="open = !open"
                   :aria-expanded="open.toString()"
                   aria-controls="faq-panel-{{ loop.index }}">
@@ -495,8 +495,7 @@
         </h3>
         <div id="faq-panel-{{ loop.index }}"
              x-show="open"
-             x-transition.opacity.duration.200ms
-             role="region">
+             x-transition.opacity.duration.200ms>
           <p class="px-2 pb-4 text-sm text-brand-navy/80 leading-relaxed">{{ item.a | safe }}</p>
         </div>
       </div>