## Why
History recording used the model captured at turn start, so switching models within a turn could apply stale image preparation and tool-output truncation rules.
## What changed
Pass explicit model metadata through conversation recording. Record model responses and tool results using their originating step's settings, and capture the current model for pending input recorded during startup interruption or task completion.
## Testing
Add regression coverage for tool results across a model switch, explicit model selection for plain and annotated history, and image input retained during interruption and completion. Extend model-switching tests to verify that prepared media and item identity survive switching back to a multimodal model in live, resumed, and forked threads.
GitOrigin-RevId: 5bc750c30c334acb9b802cb80fdea01daffa84a1
## Why
Reasoning configuration changes need to retain their position and trusted provenance when model history is persisted and replayed. Client-injected history must not be able to forge these controls.
## What changed
- Add a typed `configuration_update` response item carrying reasoning effort, including custom model-defined values.
- Persist harness-authored updates with provenance and preserve them across history reconstruction, thread resume, raw response notifications, and agent forks.
- Exclude untrusted configuration updates from model history, strip client-supplied provenance metadata, and reject configuration updates supplied as turn input.
- Export the new item through the JSON and TypeScript app-server schemas and classify it in telemetry and persistence metrics.
## Testing
- Cover serialization, provenance persistence, history filtering and rollback, resume reconstruction, and injection attempts before and after restart.
GitOrigin-RevId: eb5559d2b52b7a931621e7c9812f009ff9fb8939
Abhinav