Move metadata calculation out of client (#10589)

Model client shouldn't be responsible for this.

codex-rs/core/tests/responses_headers.rs

@@ -408,88 +408,14 @@ async fn responses_stream_includes_turn_metadata_header_for_git_workspace_e2e()
         responses::ev_response_created("resp-1"),
         responses::ev_completed("resp-1"),
     ]);
-    let provider = ModelProviderInfo {
-        name: "mock".into(),
-        base_url: Some(format!("{}/v1", server.uri())),
-        env_key: None,
-        env_key_instructions: None,
-        experimental_bearer_token: None,
-        wire_api: WireApi::Responses,
-        query_params: None,
-        http_headers: None,
-        env_http_headers: None,
-        request_max_retries: Some(0),
-        stream_max_retries: Some(0),
-        stream_idle_timeout_ms: Some(5_000),
-        requires_openai_auth: false,
-        supports_websockets: false,
-    };
 
-    let codex_home = TempDir::new().expect("failed to create TempDir");
-    let mut config = load_default_config_for_test(&codex_home).await;
-    config.model_provider_id = provider.name.clone();
-    config.model_provider = provider.clone();
-    let effort = config.model_reasoning_effort;
-    let summary = config.model_reasoning_summary;
-    let model = ModelsManager::get_model_offline(config.model.as_deref());
-    config.model = Some(model.clone());
-    let config = Arc::new(config);
-
-    let conversation_id = ThreadId::new();
-    let auth_mode = AuthMode::Chatgpt;
-    let session_source =
-        SessionSource::SubAgent(SubAgentSource::Other("turn-metadata-e2e".to_string()));
-    let model_info = ModelsManager::construct_model_info_offline(model.as_str(), &config);
-    let otel_manager = OtelManager::new(
-        conversation_id,
-        model.as_str(),
-        model_info.slug.as_str(),
-        None,
-        Some("test@test.com".to_string()),
-        Some(auth_mode),
-        false,
-        "test".to_string(),
-        session_source.clone(),
-    );
-
-    let client = ModelClient::new(
-        Arc::clone(&config),
-        None,
-        model_info,
-        otel_manager,
-        provider,
-        effort,
-        summary,
-        conversation_id,
-        session_source,
-        TransportManager::new(),
-    );
-
-    let workspace = TempDir::new().expect("workspace tempdir");
-    let cwd = workspace.path();
-
-    let mut prompt = Prompt::default();
-    prompt.input = vec![ResponseItem::Message {
-        id: None,
-        role: "user".into(),
-        content: vec![ContentItem::InputText {
-            text: "hello".into(),
-        }],
-        end_turn: None,
-        phase: None,
-    }];
+    let test = test_codex().build(&server).await.expect("build test codex");
+    let cwd = test.cwd_path();
 
     let first_request = responses::mount_sse_once(&server, response_body.clone()).await;
-    let mut first_session = client.new_session(Some(cwd.to_path_buf()));
-    let mut first_stream = first_session
-        .stream(&prompt)
+    test.submit_turn("hello")
         .await
-        .expect("stream first turn");
-    while let Some(event) = first_stream.next().await {
-        if matches!(event, Ok(ResponseEvent::Completed { .. })) {
-            break;
-        }
-    }
+        .expect("submit first turn prompt");
     assert_eq!(
         first_request
             .single_request()
@@ -539,21 +465,13 @@ async fn responses_stream_includes_turn_metadata_header_for_git_workspace_e2e()
         .trim()
         .to_string();
 
-    let repo_root = std::fs::canonicalize(cwd)
-        .unwrap_or_else(|_| cwd.to_path_buf())
-        .to_string_lossy()
-        .into_owned();
     let deadline = tokio::time::Instant::now() + std::time::Duration::from_secs(5);
     loop {
         let request_recorder = responses::mount_sse_once(&server, response_body.clone()).await;
-        let mut session = client.new_session(Some(cwd.to_path_buf()));
         tokio::time::sleep(std::time::Duration::from_millis(50)).await;
-        let mut stream = session.stream(&prompt).await.expect("stream post-git turn");
-        while let Some(event) = stream.next().await {
-            if matches!(event, Ok(ResponseEvent::Completed { .. })) {
-                break;
-            }
-        }
+        test.submit_turn("hello")
+            .await
+            .expect("submit post-git turn prompt");
 
         let maybe_header = request_recorder
             .single_request()
@@ -561,11 +479,14 @@ async fn responses_stream_includes_turn_metadata_header_for_git_workspace_e2e()
         if let Some(header_value) = maybe_header {
             let parsed: serde_json::Value = serde_json::from_str(&header_value)
                 .expect("x-codex-turn-metadata should be valid JSON");
-            let workspace = parsed
+            let workspaces = parsed
                 .get("workspaces")
                 .and_then(serde_json::Value::as_object)
-                .and_then(|workspaces| workspaces.get(&repo_root))
-                .expect("metadata should include cwd repo root workspace entry");
+                .expect("metadata should include workspaces");
+            let workspace = workspaces
+                .values()
+                .next()
+                .expect("metadata should include at least one workspace entry");
 
             assert_eq!(
                 workspace