jif a17da5e6e4 Fix first-turn model switching and rollback (#37260) ...

## Why

A model switch on the first turn has no prior turn settings to compare, and rolling that turn back could leave its model instructions in history.

## What changed

- Track the model that supplied the session's base instructions so first-turn switches inject the target model's instructions, including the selected personality.
- Preserve inherited custom base instructions when starting from an empty fork.
- Remove first-turn model-switch developer content during rollback so retries and cold resumes do not retain or duplicate stale instructions.

## Testing

Add integration coverage for first-turn switches, personality changes, empty-prefix forks, rollback retries, and cold resume.

GitOrigin-RevId: 9df532e9e337521ad3b315b77f8c98e039fb384e

2026-08-06 11:03:31 +00:00

..

common

Allow injecting model catalog caches (#36992)

2026-08-04 23:04:11 +00:00

remote_env_windows

Scope runtime workspace roots to execution environments (#32952)

2026-07-14 04:41:08 +00:00

suite

Fix first-turn model switching and rollback (#37260)

2026-08-06 11:03:31 +00:00

all.rs

[codex] Use expect in integration tests (#28441)

2026-06-15 21:53:47 -07:00

responses_headers.rs

Allow custom providers to opt into standalone web search (#34846)

2026-07-23 00:02:15 +00:00