Fix anti-patterns flagged by Impeccable on the homepage

- Hero demo card no longer uses <h3> for its title, fixing the
  h1 → h3 skip in the document outline. The "after" card now uses
  <p class="impeccable-title"> matching the structure of the
  corresponding "before" slop-card (which already used a <div>).
- Constrains .changelog-items and .faq-answer to max-width: 70ch so
  long bullet points and FAQ paragraphs don't exceed comfortable
  reading length (was hitting ~135 chars/line).
- Bumps the destructive-action warning text in the /clarify command
  demo from #a16207 to #854d0e on #fef3c7, lifting the contrast from
  4.4:1 (just below WCAG AA) to ~6.4:1.

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

public/css/workflow.css

@@ -1116,6 +1116,7 @@
   padding-left: var(--spacing-md);
   color: var(--color-charcoal);
   line-height: 1.7;
+  max-width: 70ch;
 }
 
 .changelog-items li {
@@ -1233,6 +1234,7 @@
   padding: 0 0 var(--spacing-md);
   color: var(--color-charcoal);
   line-height: 1.7;
+  max-width: 70ch;
   animation: faqFadeIn 0.3s var(--ease-out);
 }