## Why
Local compaction stores generated summaries with the `user` wire role, but those summaries are not user authorization. Guardian transcripts need to preserve that distinction when reviewing compacted history.
## What changed
Classify messages marked with `compaction.summary` as assistant entries in Guardian transcripts, while preserving the attribution of actual user messages.
## Testing
Add transcript collection coverage and regression tests for both line and JSON transcripts that verify generated summaries are attributed to the assistant and original user instructions remain attributed to the user.
GitOrigin-RevId: 66183028ce70a2500d47d3347b110f95471ba868