renderer: fix title key null check

src/renderer/components/layout/HeaderLayout.vue

@@ -3,6 +3,7 @@ import { useRoute, useRouter } from 'vue-router'
 
 const router = useRouter()
 const route = useRoute()
+const titleKey: string = (route?.meta?.titleKey || 'title.main') as string
 
 const handleRoute = (path: string): void => {
 	router.push(path)
@@ -14,7 +15,7 @@ const isCurrentRoute = (path: string): boolean => {
 </script>
 <template>
 	<v-app-bar color="primary" density="compact">
-		<v-app-bar-title>{{ $t($route.meta.titleKey || 'title.main') }}</v-app-bar-title>
+		<v-app-bar-title>{{ $t(titleKey) }}</v-app-bar-title>
 		<template #append>
 			<v-btn
 				prepend-icon="mdi-home"