Show Reddit post age in conversations

tests/web/conversations-route.test.ts

@@ -296,6 +296,7 @@ describe('conversations route', () => {
       chatRoomId: 'room-alice', subreddit: 'example', postTitle: 'Exact source post',
       postUrl: 'https://www.reddit.com/r/example/comments/post-exact/exact_source_post/',
       postImageUrl: 'https://i.redd.it/exact-source.jpg',
+      postCreatedAt: 8,
     };
     const latestRecipientOrigin = { ...roomOrigin, postId: 'wrong-latest-post', postTitle: 'Wrong post' };
     const context = {
@@ -318,7 +319,7 @@ describe('conversations route', () => {
     const body = await response.json();
     expect(body.triggeringPost).toEqual({
       id: 'post-exact', subreddit: 'example', title: 'Exact source post',
-      url: roomOrigin.postUrl, imageUrl: roomOrigin.postImageUrl, sentAt: 9,
+      url: roomOrigin.postUrl, imageUrl: roomOrigin.postImageUrl, postedAt: 8, sentAt: 9,
     });
     expect(body.messages[0]).toMatchObject({ text: 'Hello', isAi: true });
     expect(context.repos.messages.getLatestByRecipient).not.toHaveBeenCalled();