Add Guardian V2 analytics events (#42144)

## What changed

- Emit `codex_guardian_v2_classification` events with the outcome, risk
  level, duration, model, and thread attribution.
- Emit `codex_guardian_v2_fast_decision` events when Guardian V2 approves an
  action without a full review.
- Add `guardian_v2_enabled` to turn analytics, accounting for review scope
  and model requirements.

## Testing

- Extend the Guardian V2 app-server coverage to verify event payloads,
  attribution, enablement state, and scoped event emission.

GitOrigin-RevId: 0805975f8e8f9d954aa1058ea8c60545a090ae74

codex-rs/core/src/session/turn.rs

@@ -1029,6 +1029,18 @@ async fn track_turn_resolved_config_analytics(
                 .and_then(ServiceTier::from_request_value),
             approval_policy: turn_context.approval_policy(),
             approvals_reviewer: turn_context.config.approvals_reviewer,
+            guardian_v2_enabled: sess
+                .services
+                .thread_extension_data
+                .get::<codex_extension_api::GuardianV2Enabled>()
+                .is_some_and(|state| {
+                    state.computer_use_only
+                        || !turn_context
+                            .config
+                            .config_layer_stack
+                            .requirements()
+                            .auto_review_required_for_model(&turn_context.model_info().slug)
+                }),
             sandbox_network_access: turn_context.network_sandbox_policy().is_enabled(),
             collaboration_mode: turn_context.mode(),
             personality: turn_context.personality(),