Fix legal-page autolink color, add Blog breadcrumb, revert breadcrumb color

- RichText.tsx: Lexical's auto-detected "autolink" nodes (a typed-out
  email/URL, as opposed to an editor-inserted link) fell through to
  Payload's unstyled default converter — only "link" was overridden.
  AGB's Vertragspartner email rendered as plain black text because of
  this. Both node types now get the same text-brand/hover:underline
  treatment.
- Breadcrumb color revert: the breadcrumb Startseite links across the
  4 legal pages/shop should stay their original hover:text-brand
  treatment — only the actual content/contact links needed the
  always-brand-colored style, not page-level breadcrumbs.
- /blog was the one page missing both a breadcrumb and the
  text-h-feature heading size every other section page (/shop, legal
  pages) already uses — added to match.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018unaXmuzVA8ct1b6WoyP1U

app/components/RichText.tsx

@@ -160,6 +160,16 @@ function buildConverters(quoteLabel: string): JSXConvertersFunction {
         {nodesToJSX({ nodes: node.children })}
       </a>
     ),
+    // Lexical auto-detects a typed-out URL/email as its own "autolink" node,
+    // distinct from an editor-inserted "link" node — falls through to
+    // Payload's unstyled default converter without this, which is why the
+    // Impressum/AGB's typed-in-place mailto addresses rendered as plain
+    // black text instead of matching every editor-inserted link.
+    autolink: ({ node, nodesToJSX }) => (
+      <a href={node.fields?.url ?? "#"} className="text-brand hover:underline">
+        {nodesToJSX({ nodes: node.children })}
+      </a>
+    ),
     // Lexical's native blockquote feature — used by every post written
     // before Blocks existed. Kept working exactly as before (own comment on
     // Posts.ts's `content` field editor config on why this stays enabled