Missing accessible name on post card on timelines

## Bug description

On all timelines, when navigating by keyboard shortcuts (J and K) with a screen reader on (e.g., NVDA), the screen reader reports only a link with no text, which is the first identifiable element of each post's card.

- Site: phanpy.social
- Site version: 2024.08.31.1b8ab47
- Instance: bolha.us

## To Reproduce

1. Go to https://phanpy.social
2. With NVDA on, enter focus mode by pressing NVDA + Space.
3. Jump some posts by pressing J
4. Jump back a few posts by pressing K
5. Notice that NVDA only announces "link"

## Expected behavior

The screen reader should announce the post content in a way that is meaningful, like it happens on Mastodon's default web app, including user who posted, post content, media descriptions and other related information.

## Desktop
- OS: Windows 11
- Browser: Brave
- Version: 1.69.160 Chromium: 128.0.6613.114

## Additional context

- NVDA version: 2024.3

Start by reproducing the issue on phanpy.social with NVDA, using J and K to focus post cards, then inspect the first link in a timeline post. Compare the announcement with Mastodon's default web app and verify that the post author, content, media descriptions, and related information are meaningfully announced.

Written by the indexing model from the issue text.