Move TUI on top of app server (parallel code) (#14717)

This PR replicates the `tui` code directory and creates a temporary
parallel `tui_app_server` directory. It also implements a new feature
flag `tui_app_server` to select between the two tui implementations.

Once the new app-server-based TUI is stabilized, we'll delete the old
`tui` directory and feature flag.

codex-rs/cloud-requirements/src/lib.rs

@@ -16,6 +16,7 @@ use chrono::Duration as ChronoDuration;
 use chrono::Utc;
 use codex_backend_client::Client as BackendClient;
 use codex_core::AuthManager;
+use codex_core::auth::AuthCredentialsStoreMode;
 use codex_core::auth::CodexAuth;
 use codex_core::auth::RefreshTokenError;
 use codex_core::config_loader::CloudRequirementsLoadError;
@@ -715,6 +716,20 @@ pub fn cloud_requirements_loader(
     })
 }
 
+pub fn cloud_requirements_loader_for_storage(
+    codex_home: PathBuf,
+    enable_codex_api_key_env: bool,
+    credentials_store_mode: AuthCredentialsStoreMode,
+    chatgpt_base_url: String,
+) -> CloudRequirementsLoader {
+    let auth_manager = AuthManager::shared(
+        codex_home.clone(),
+        enable_codex_api_key_env,
+        credentials_store_mode,
+    );
+    cloud_requirements_loader(auth_manager, chatgpt_base_url, codex_home)
+}
+
 fn parse_cloud_requirements(
     contents: &str,
 ) -> Result<Option<ConfigRequirementsToml>, toml::de::Error> {