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/utils/config.ts

@@ -132,7 +132,7 @@ export type AppConfig = {
   fullAutoErrorMode?: FullAutoErrorMode;
   memory?: MemoryConfig;
   /** Whether to enable desktop notifications for responses */
-  notify: boolean;
+  notify?: boolean;
 
   /** Disable server-side response storage (send full transcript each request) */
   disableResponseStorage?: boolean;