codex: migrate (more) app-server thread history reads to ThreadStore (#20575)

Migrate token usage replay, rollback responses, and detached review
setup (a special case of forking) to be served from ThreadStore reads
rather direct rollout files.

- replay restored token usage from already-loaded `RolloutItem` history
instead of reopening `Thread.path`
- rebuild rollback responses from loaded `ThreadStore` snapshots and
history
- start detached reviews from store-backed parent history and stored
review-thread metadata
- remove obsolete app-server rollout-summary helper code that became
dead after the store-backed migration
- preserve response/notification ordering for resume, fork, rollback,
and detached review flows
- add integration test coverage for the affected paths

codex-rs/thread-store/src/local/read_thread.rs

@@ -70,6 +70,11 @@ pub(super) async fn read_thread(
         })?;
 
     let mut thread = read_thread_from_rollout_path(store, path).await?;
+    if !params.include_archived && thread.archived_at.is_some() {
+        return Err(ThreadStoreError::InvalidRequest {
+            message: format!("thread {} is archived", thread.thread_id),
+        });
+    }
     attach_history_if_requested(&mut thread, params.include_history).await?;
     Ok(thread)
 }