refactor(frontend): reduce type errors

packages/frontend/src/pages/settings/profile.vue

@@ -140,8 +140,8 @@ const profile = reactive({
 	location: $i.location,
 	birthday: $i.birthday,
 	lang: $i.lang,
-	isBot: $i.isBot,
-	isCat: $i.isCat,
+	isBot: $i.isBot ?? false,
+	isCat: $i.isCat ?? false,
 });
 
 watch(() => profile, () => {

packages/frontend/src/pizzax.ts

@@ -225,7 +225,10 @@ export class Storage<T extends StateDef> {
 	 * 特定のキーの、簡易的なgetter/setterを作ります
 	 * 主にvue場で設定コントロールのmodelとして使う用
 	 */
-	public makeGetterSetter<K extends keyof T>(key: K, getter?: (v: T[K]) => unknown, setter?: (v: unknown) => T[K]) {
+	public makeGetterSetter<K extends keyof T>(key: K, getter?: (v: T[K]) => unknown, setter?: (v: unknown) => T[K]): {
+		get: () => T[K]['default'];
+		set: (value: T[K]['default']) => void;
+	} {
 		const valueRef = ref(this.state[key]);
 
 		const stop = watch(this.reactiveState[key], val => {