Update Codex provider migration test expectations

src-tauri/tests/import_export_sync.rs

@@ -210,7 +210,7 @@ experimental_bearer_token = "stored-bearer-key"
 }
 
 #[test]
-fn sync_codex_provider_preserves_live_model_provider_id_for_history() {
+fn sync_codex_provider_preserves_user_model_provider_id_after_migration() {
     let _guard = test_mutex().lock().expect("acquire test mutex");
     reset_test_fs();
 
@@ -264,8 +264,8 @@ requires_openai_auth = true
 
     assert_eq!(
         parsed.get("model_provider").and_then(|v| v.as_str()),
-        Some("custom"),
-        "legacy ConfigService sync should collapse third-party providers into the stable \"custom\" history bucket"
+        Some("aihubmix"),
+        "ConfigService sync should preserve user-editable model_provider after the one-time migration"
     );
 
     let model_providers = parsed
@@ -273,12 +273,12 @@ requires_openai_auth = true
         .and_then(|v| v.as_table())
         .expect("model_providers should exist");
     assert!(
-        model_providers.get("aihubmix").is_none(),
-        "provider-specific target id should not be written to live config"
+        model_providers.get("custom").is_none(),
+        "provider sync should not force user-edited provider ids back to custom"
     );
     assert_eq!(
         model_providers
-            .get("custom")
+            .get("aihubmix")
             .and_then(|v| v.get("base_url"))
             .and_then(|v| v.as_str()),
         Some("https://aihubmix.example/v1")