Expose ChatGPT user IDs in account/read responses (#60004)

## What changed

Add a nullable `userId` to `GetAccountResponse`, populated from the same authenticated account snapshot as the rest of the response. ChatGPT and personal access token sessions return the canonical ChatGPT user ID when available; API-only and signed-out sessions return `null`.

Update the cloud client, generated schemas, TypeScript and Python types, and account identity documentation. Default missing IDs to `None` when deserializing responses from older app servers.

## Testing

Extend account response tests to check ChatGPT and personal access token user IDs, null IDs for other providers and signed-out sessions, and ID changes when switching providers with saved ChatGPT credentials.

GitOrigin-RevId: 7ad3da3cfc835c4d08d03c8e91b06cd7e007d874

codex-rs/app-server-protocol/src/protocol/common_tests.rs

@@ -55,12 +55,14 @@ fn client_response_jsonrpc_parts_preserve_payloads_and_request_ids() -> Result<(
         ),
         (
             ClientResponsePayload::GetAccount(v2::GetAccountResponse {
+                user_id: None,
                 account: Some(v2::Account::ApiKey {}),
                 requires_openai_auth: false,
                 workspace_routing: None,
             }),
             json!({
                 "account": { "type": "apiKey" },
+                "userId": null,
                 "requiresOpenaiAuth": false,
                 "workspaceRouting": null,
             }),

codex-rs/app-server-protocol/src/protocol/v2/account.rs

@@ -586,6 +586,9 @@ pub struct GetAccountParams {
 #[ts(export_to = "v2/")]
 pub struct GetAccountResponse {
     pub account: Option<Account>,
+    /// ChatGPT user ID belonging to this account response, when available.
+    #[serde(default)]
+    pub user_id: Option<String>,
     pub requires_openai_auth: bool,
     #[experimental("account/read.workspaceRouting")]
     pub workspace_routing: Option<WorkspaceRouting>,