fix(agent-loop): notify type (#608)

## Description

The `as AppConfig` type assertion in the constructor may introduce
potential type safety risks. Removing the assertion and making `notify`
an optional parameter could enhance type robustness and prevent
unexpected runtime errors.

close: #605

codex-cli/src/components/chat/terminal-chat.tsx

@@ -141,7 +141,7 @@ export default function TerminalChat({
   additionalWritableRoots,
   fullStdout,
 }: Props): React.ReactElement {
-  const notify = config.notify;
+  const notify = Boolean(config.notify);
   const [model, setModel] = useState<string>(config.model);
   const [provider, setProvider] = useState<string>(config.provider || "openai");
   const [lastResponseId, setLastResponseId] = useState<string | null>(null);