feat(background-agent): integrate into main plugin

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/index.ts

@@ -11,3 +11,4 @@ export { createAnthropicAutoCompactHook } from "./anthropic-auto-compact";
 export { createThinkModeHook } from "./think-mode";
 export { createClaudeCodeHooksHook } from "./claude-code-hooks";
 export { createRulesInjectorHook } from "./rules-injector";
+export { createBackgroundNotificationHook } from "./background-notification";