Honor turn token budgets in Guardian review rollover (#41221)

## What changed

Resolve the review model's token budget from the parent turn's original
configuration and model-default setting when deciding whether a Guardian
follow-up review needs context rollover. This preserves explicit token-budget
preferences instead of unconditionally applying the review model's defaults.

GitOrigin-RevId: cb3adaea7dad22f4975d84c6ee62dfc2bfbddbb9

codex-rs/core/src/guardian/review_session.rs

@@ -956,6 +956,7 @@ async fn run_review_on_session(
         && crate::session::context_window::context_window_token_status_for_model(
             review_session.session.as_ref(),
             &params.spawn_config,
+            params.parent_context.turn(),
             &model_info,
         )
         .await

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

@@ -37,10 +37,15 @@ pub(crate) async fn context_window_token_status(
 pub(crate) async fn context_window_token_status_for_model(
     sess: &Session,
     config: &Config,
+    turn_context: &TurnContext,
     model_info: &ModelInfo,
 ) -> ContextWindowTokenStatus {
     let mut config = config.clone();
-    super::token_budget::apply_model_defaults(&mut config, model_info);
+    config.token_budget = super::token_budget::resolve_token_budget(
+        turn_context.configured_token_budget.as_ref(),
+        turn_context.use_model_token_budget_defaults,
+        model_info,
+    );
     context_window_token_status_with_config(sess, &config, model_info).await
 }