codex: auto-unarchive archived sessions safely on resume

Preserve the auto-unarchive-on-resume behavior while keeping archived-session lookup safe. This carries the rollout lookup hardening, the resume path updates, and the cross-platform guardian/TUI test fixes needed for current CI.

codex-rs/core/tests/suite/rollout_list_find.rs

@@ -9,6 +9,7 @@ use codex_core::RolloutRecorder;
 use codex_core::RolloutRecorderParams;
 use codex_core::config::ConfigBuilder;
 use codex_core::find_archived_thread_path_by_id_str;
+use codex_core::find_or_unarchive_thread_path_by_id_str;
 use codex_core::find_thread_path_by_id_str;
 use codex_core::find_thread_path_by_name_str;
 use codex_protocol::ThreadId;
@@ -219,3 +220,74 @@ async fn find_archived_locates_rollout_file_by_id() {
 
     assert_eq!(found, Some(expected));
 }
+
+#[tokio::test]
+async fn find_thread_path_by_id_str_does_not_unarchive_archived_rollout() {
+    let home = TempDir::new().unwrap();
+    let id = Uuid::new_v4();
+    let archived = write_minimal_rollout_with_id_in_subdir(home.path(), "archived_sessions", id);
+
+    let found = find_thread_path_by_id_str(home.path(), &id.to_string())
+        .await
+        .unwrap();
+
+    assert_eq!(found, None);
+    assert!(archived.exists());
+}
+
+#[tokio::test]
+async fn find_or_unarchive_restores_archived_rollout_file_by_id() {
+    let home = TempDir::new().unwrap();
+    let id = Uuid::new_v4();
+    let archived = write_minimal_rollout_with_id_in_subdir(home.path(), "archived_sessions", id);
+    let file_name = archived.file_name().unwrap().to_owned();
+    let expected_restored = home.path().join("sessions/2024/01/01").join(file_name);
+
+    let found = find_or_unarchive_thread_path_by_id_str(home.path(), &id.to_string())
+        .await
+        .unwrap();
+
+    assert_eq!(found, Some(expected_restored.clone()));
+    assert!(expected_restored.exists());
+    assert!(!archived.exists());
+
+    let archived_found = find_archived_thread_path_by_id_str(home.path(), &id.to_string())
+        .await
+        .unwrap();
+    assert_eq!(archived_found, None);
+}
+
+#[tokio::test]
+async fn find_does_not_move_unrelated_file_for_stale_archived_db_path() {
+    let home = TempDir::new().unwrap();
+    let requested_id = Uuid::new_v4();
+    let requested_thread_id = ThreadId::from_string(&requested_id.to_string()).unwrap();
+    let unrelated_id = Uuid::new_v4();
+    let unrelated_active_path = write_minimal_rollout_with_id(home.path(), unrelated_id);
+
+    upsert_thread_metadata(
+        home.path(),
+        requested_thread_id,
+        unrelated_active_path.clone(),
+    )
+    .await;
+    let runtime = StateRuntime::init(home.path().to_path_buf(), "test-provider".to_string())
+        .await
+        .unwrap();
+    runtime.mark_backfill_complete(None).await.unwrap();
+    runtime
+        .mark_archived(
+            requested_thread_id,
+            unrelated_active_path.as_path(),
+            Utc::now(),
+        )
+        .await
+        .unwrap();
+
+    let found = find_or_unarchive_thread_path_by_id_str(home.path(), &requested_id.to_string())
+        .await
+        .unwrap();
+
+    assert_eq!(found, None);
+    assert!(unrelated_active_path.exists());
+}