Route MCP elicitations through the shared approval decision path (#43447)

## What changed

- Use `decide_approval` for MCP elicitations, carrying the effective approval policy, reviewer, and synchronous-review requirement into the decision.
- Preserve unsupported form and URL elicitations for user review.
- Use `computer_use_review_required()` for review evidence, session policy, and turn metadata so model policy takes precedence over the legacy flag.
- Derive strict-review notifications from each assessment's review reason.

## Testing

Add coverage for model policy precedence, user and full-access modes, sensitive elicitations, independent code-mode and nested-tool policies, cached score reuse, and user review of unsupported elicitations.

GitOrigin-RevId: d0a9c40572dca7b3dbf876230d2162b72728084d

codex-rs/app-server/src/bespoke_event_handling.rs

@@ -97,7 +97,6 @@ use codex_app_server_protocol::item_event_to_server_notification;
 use codex_core::CodexThread;
 use codex_core::ThreadManager;
 use codex_features::Feature;
-use codex_guardian_v2::StrictReviewReason;
 use codex_protocol::ThreadId;
 use codex_protocol::items::CollabAgentTool as CoreCollabAgentTool;
 use codex_protocol::items::TurnItem as CoreTurnItem;
@@ -355,21 +354,16 @@ pub(crate) async fn apply_bespoke_event_handling(
             );
             outgoing.send_server_notification(notification).await;
             if assessment.status == codex_protocol::protocol::GuardianAssessmentStatus::InProgress
-                && match assessment.review_reason {
-                    Some(reason) => matches!(
-                        reason,
+                && matches!(
+                    assessment.review_reason,
+                    Some(
                         codex_protocol::approvals::GuardianReviewReason::ElevatedRisk
                             | codex_protocol::approvals::GuardianReviewReason::StaleScore
                             | codex_protocol::approvals::GuardianReviewReason::IncompatibleCompaction
                             | codex_protocol::approvals::GuardianReviewReason::ScoringFailure
                             | codex_protocol::approvals::GuardianReviewReason::AuthorizationChanged
-                    ),
-                    // MCP elicitations migrate to per-approval reasons next.
-                    None => conversation
-                        .thread_extension_data()
-                        .remove::<StrictReviewReason>()
-                        .is_some(),
-                }
+                    )
+                )
             {
                 outgoing
                     .send_server_notification(ServerNotification::StrictReviewRequired(