experimental.chat.messages.transform isn't triggered in compaction #17820

Description

The messages transform hook is not triggered by the compaction process, leading to any message modifications done not showing up in the request when compaction is triggered.

Plugins

https://github.com/Opencode-DCP/opencode-dynamic-context-pruning

OpenCode version

1.2.27

Steps to reproduce

1. create a plugin that uses the experimental.chat.messages.transform hook
2. send a normal prompt, it can be modified by the hook
3. triggering /compact and the changes from the hook are not applied

Screenshot and/or share link

No response

Operating System

Arch Linux

Terminal

Ghostty