Feature request: PostToolUse hooks that can modify tool output

Currently PostToolUse hooks can view but not modify a tools output. It would be nice to have e.g. a "transform"-type hook that can modify a tools response before it gets returned back to the model.

Example use case would be things like GitHub's MCP server, which returns extremely verbose responses by default. It would be nice to be able to add a hook that uses jq to prune that down to a reasonable size before the model sees it.