Avatars (profile pictures) don't load unless I clear cache

**Describe the bug**
A clear and concise description of what the bug is.
- phanpy.social
- Which site version: 2024.06.03.0a6030c
- Which instance: inductive.space

**To Reproduce**
Steps to reproduce the behavior:
1. Go to Phanpy
2. Avatars will not load, reloading normally will not fix this
3. Reloading and clearing cache (cmd + shift + r) will fix this

**Expected behavior**
Avatars should load on the first try

**Screenshots**
https://github.com/cheeaun/phanpy/assets/2727095/d0b6ca4a-a1fb-4c84-9fb5-aa2f01625fb1

**Desktop (please complete the following information):**
- OS: macOS, Linux
- Browser Arc (Chrome 125 engine), Firefox 126

Start by reproducing the avatar-loading failure on phanpy.social with the listed Arc and Firefox versions, then inspect the avatar request and caching behavior. Done means avatars load without requiring a cache-clearing hard refresh.

Written by the indexing model from the issue text.