fix: og image generation

app/books/iso/[mantra]/page.tsx

@@ -1,3 +1,6 @@
+export const dynamic = "force-dynamic";
+
+import type { Metadata } from "next";
 import Link from "next/link";
 import { notFound } from "next/navigation";
 import {
@@ -7,6 +10,7 @@ import {
   type IsoIntroSegment,
   type IsoSidebarItem,
 } from "@/lib/iso";
+import { ogForChapter, extractQuoteFromHl, buildOgMeta } from "@/lib/og";
 import { PageHeader } from "@/components/page-header";
 import { Card, CardContent } from "@/components/ui/card";
 import { buttonVariants } from "@/components/ui/button";
@@ -28,6 +32,40 @@ function isIntroSegment(
   return "paragraphs" in content && "order" in content;
 }
 
+// ---------------------------------------------------------------------------
+// Metadata
+// ---------------------------------------------------------------------------
+
+export async function generateMetadata({
+  params,
+  searchParams,
+}: {
+  params: Promise<{ mantra: string }>;
+  searchParams: Promise<Record<string, string | string[] | undefined>>;
+}): Promise<Metadata> {
+  const { mantra: slug } = await params;
+  const sp = await searchParams;
+
+  const quote = extractQuoteFromHl(sp);
+  if (quote) {
+    return buildOgMeta({
+      title: "Śrī Īśopaniṣad",
+      detail: `Mantra ${slug}`,
+      quote,
+    });
+  }
+
+  const content = await getIsoContent(slug);
+  const isVerse_ = content && "mantra" in content && "devanagari" in content;
+  const title = isVerse_
+    ? `${(content as IsoVerse).reference}: ${(content as IsoVerse).title}`
+    : content && "title" in content
+      ? (content as IsoIntroSegment).title
+      : `Mantra ${slug}`;
+
+  return ogForChapter("iso", title);
+}
+
 // ---------------------------------------------------------------------------
 // Page
 // ---------------------------------------------------------------------------