Incomplete support for posts from Castopod

**Describe the bug**
Posts from Castopod does not show in timelines, but boosts show in carousels, and posts are accessible trough searching for the URL.

**To Reproduce**

Hi. I just posted on my Castopod instance. I follow my Castopod account from my Mastodon account, but after publishing the Castopod post did not show up in my home feed in Phanpy, but it did show in my home feed directly on Mastodon. I found it in Phanpy by searching for its [URL](https://borge.forteller.net/@BorgeForteller/posts/ba2478a6-2043-430f-831c-fef415c3079d), and then I boosted it. After boosting I opened my Mastodon account in Phanpy and noticed that it did not appear in my timeline (I made sure showing boosts where turned on). But it does show in boost carousels.

**Expected behavior**
Posts on Castopod should behave like any other post

**Screenshots**
The boosted post is not visible in my timeline:

It does show in the boost carousel:

**Desktop (please complete the following information):**
- OS: Nobara Linux
- Browser Firefox
- Version 119

Thank you again!

Start by reproducing the issue with the linked Castopod post URL and compare how it is handled in the home timeline, search results, and boost carousel. Done means Castopod posts appear in followed-account timelines and boosted posts appear in the timeline like other posts.

Written by the indexing model from the issue text.