fix(blog): restore TOC, list styling, and dynamic OG images

This commit reapplies fixes directly to main after reverting an accidental feature branch merge.

chore(release): bump version to 2.2.6

app/[locale]/blog/[slug]/page.tsx

@@ -1,12 +1,18 @@
 import { notFound, redirect } from 'next/navigation';
 import JsonLd from '@/components/JsonLd';
 import { SITE_URL } from '@/lib/schema';
-import { getPostBySlug, getAdjacentPosts, getReadingTime } from '@/lib/blog';
+import {
+  getPostBySlug,
+  getAdjacentPosts,
+  getReadingTime,
+  extractLexicalHeadings,
+} from '@/lib/blog';
 import { Metadata } from 'next';
 import Link from 'next/link';
 import Image from 'next/image';
 import PostNavigation from '@/components/blog/PostNavigation';
 import PowerCTA from '@/components/blog/PowerCTA';
+import TableOfContents from '@/components/blog/TableOfContents';
 import { Heading } from '@/components/ui';
 import { setRequestLocale } from 'next-intl/server';
 import BlogEngagementTracker from '@/components/analytics/BlogEngagementTracker';
@@ -67,6 +73,10 @@ export default async function BlogPost({ params }: BlogPostProps) {
 
   const { prev, next, isPrevRandom, isNextRandom } = await getAdjacentPosts(post.slug, locale);
 
+  // Convert Lexical content into a plain string to estimate reading time roughly
+  // Extract headings for TOC
+  const headings = extractLexicalHeadings(post.content?.root || post.content);
+
   // Convert Lexical content into a plain string to estimate reading time roughly
   const rawTextContent = JSON.stringify(post.content);
 
@@ -88,7 +98,6 @@ export default async function BlogPost({ params }: BlogPostProps) {
               alt={post.frontmatter.title}
               fill
               priority
-              quality={90}
               className="object-cover"
               sizes="100vw"
               style={{
@@ -232,10 +241,10 @@ export default async function BlogPost({ params }: BlogPostProps) {
             </div>
           </div>
 
-          {/* Right Column: Sticky Sidebar - Temporarily Hidden without ToC */}
+          {/* Right Column: Sticky Sidebar - TOC */}
           <aside className="sticky-narrative-sidebar hidden lg:block">
-            <div className="space-y-12">
-              {/* Future Payload Table of Contents Implementation */}
+            <div className="space-y-12 lg:sticky lg:top-32">
+              <TableOfContents headings={headings} locale={locale} />
             </div>
           </aside>
         </div>