fix: make auth request optional

Author: AlexandrSuhinin

src/index.ts

@@ -15,10 +15,10 @@ const acpJsonStream = createJsonStream(process.stdin, process.stdout);
 function createAgent(connection: acp.AgentSideConnection): CodexACPAgent {
     const configString = process.env["CODEX_CONFIG"];
     const config = configString ? JSON.parse(configString) : undefined;
-    const modelProvider = process.env["MODEL_PROVIDER"];
+    const modelProvider= process.env["MODEL_PROVIDER"];
     const authRequestString = process.env["DEFAULT_AUTH_REQUEST"];
     const parsedRequest = authRequestString ? JSON.parse(authRequestString) : undefined;
-    const defaultAuthRequest = isCodexAuthRequest(parsedRequest) ? parsedRequest : undefined;
+    const defaultAuthRequest = parsedRequest && isCodexAuthRequest(parsedRequest) ? parsedRequest : undefined;
     return new CodexACPAgent(connection, appServerConnection, config, modelProvider, defaultAuthRequest);
 }