fix: use EventPointer for repost replyTo in NIP-10 adapter

Apply the same relay hints fix to the repostToMessage function that was
added in a recent main commit.

src/lib/chat/adapters/nip-10-adapter.ts

@@ -943,9 +943,11 @@ export class Nip10Adapter extends ChatProtocolAdapter {
     repostEvent: NostrEvent,
     conversationId: string,
   ): Message {
-    // Find what event is being reposted (e-tag)
+    // Find what event is being reposted (e-tag) - use full pointer with relay hints
     const eTag = repostEvent.tags.find((t) => t[0] === "e");
-    const replyTo = eTag?.[1];
+    const replyTo = eTag
+      ? (getEventPointerFromETag(eTag) ?? undefined)
+      : undefined;
 
     return {
       id: repostEvent.id,