feat: share post to other apps

lib/share-og.ts

@@ -23,6 +23,8 @@ import {
   ogForLetter,
   ogForMagazine,
   ogForOtherDocument,
+  ogForPost,
+  ogForProfile,
   ogForTranscription,
   ogForVerse,
 } from "@/lib/og";
@@ -115,6 +117,10 @@ export async function buildShareOgMeta(fullPath: string): Promise<Metadata> {
         return parts.length >= 3
           ? await ogForOtherDocPath(parts[1], parts[2], sp)
           : ogDefault();
+      case "u":
+        // /u/<handle> → profile share
+        // /u/<handle>/posts#post-<id> → post share (post id in u.hash)
+        return await ogForProfilePath(parts, u.hash);
       default:
         return ogWithFallbackQuote("Prabhupāda Says", sp);
     }
@@ -365,6 +371,74 @@ async function ogForOtherDocPath(
 // Fallback
 // ---------------------------------------------------------------------------
 
+// ---------------------------------------------------------------------------
+// Profile + post share dispatch
+// ---------------------------------------------------------------------------
+
+type PublicProfileForOg = {
+  handle: string;
+  name: string;
+  post_count?: number;
+};
+
+type PostForOg = {
+  id: string;
+  caption: string;
+  source_title?: string | null;
+  author_name?: string | null;
+  author_handle?: string | null;
+};
+
+/**
+ * Resolve `/u/<handle>` and `/u/<handle>/posts#post-<id>` share targets
+ * to the correct OG card. The hash carries the post id when the share
+ * is a single-post link (built by SharePostSheet); without a hash we
+ * fall back to a profile card for the handle.
+ */
+async function ogForProfilePath(
+  parts: string[],
+  hash: string,
+): Promise<Metadata> {
+  if (parts.length < 2) return ogDefault();
+  const handle = parts[1];
+
+  // Post share: /u/<handle>/posts with `#post-<id>` fragment.
+  if (parts.length >= 3 && parts[2] === "posts") {
+    const m = hash.match(/^#post-(.+)$/);
+    if (m) {
+      const postID = m[1];
+      try {
+        const post = await bff<PostForOg>(
+          `/posts/${encodeURIComponent(postID)}`,
+          { revalidate: 60 },
+        );
+        if (post) return ogForPost(post);
+      } catch {
+        // fall through to profile-level card
+      }
+    }
+    // No post id → treat as a feed share for the profile.
+  }
+
+  // Profile share: /u/<handle>
+  try {
+    const profile = await bff<PublicProfileForOg>(
+      `/u/${encodeURIComponent(handle)}`,
+      { revalidate: 60 },
+    );
+    if (profile) {
+      return ogForProfile({
+        handle: profile.handle,
+        name: profile.name,
+        postCount: profile.post_count,
+      });
+    }
+  } catch {
+    // fall through
+  }
+  return ogDefault();
+}
+
 function ogWithFallbackQuote(
   title: string,
   sp: URLSearchParams,