## What changed
- Add a policy prompt and output contract for synchronous Guardian reviews.
- Build reviewer thread options with a preferred review model, low reasoning effort when supported, and a fallback to the parent model and effective effort.
- Isolate reviewer sessions from parent instructions, MCP servers, optional features, and write access while preserving read restrictions, resolved environments, managed network constraints, and rollout persistence.
- Mark prepared threads as internal Guardian review sessions for later host-managed startup.
## Testing
- Cover reviewer isolation, read-only environment inheritance, review-model overrides, and parent-model fallback behavior.
GitOrigin-RevId: 5133be99674b64e06e19e7f2dbc86439e1678790
## What changed
- Move the Guardian thread lifecycle contributor and subagent-spawn context into `codex-guardian-v2`.
- Install the lifecycle contributor and asynchronous risk scorer through a single extension entry point.
- Remove the redundant `codex-guardian` crate and group the existing scorer implementation under `async_scorer`.
GitOrigin-RevId: 97141190c843e588b8c09c9ccd3fe00e1fae39a4
## What changed
- Replace the minimal default classifier prompt with predictive security-review guidance covering authorization, action risk, untrusted evidence, and browser or computer use.
- Trigger full Guardian review at an `action_risk` score of `0.5` or higher for the new default prompt, while retaining the `0.8` calibration for custom and model-provided prompts unless they specify a threshold.
- Render security policy configuration into prompt templates before enforcing the classifier instruction token limit. Prompts without the policy placeholder retain the existing append-and-truncate behavior.
## Testing
- Cover default, custom, and model-provided prompt thresholds and precedence.
- Verify policy substitution, truncation, sampling requests, and full review at the threshold boundary.
GitOrigin-RevId: 7aad9e2d8c9fbea453dc52147a3d0a46bf191aec
## What changed
- Add the `codex-guardian-v2` crate with an extension install entry point that does not register contributors yet.
- Register the crate in the Cargo workspace and add its Bazel target.
GitOrigin-RevId: 7c0c9479c6722d65f0f0dad9b0fd4a756e4649b3