feat(frontend): 画面に雪を降らせる機能を復活

packages/frontend/src/boot/main-boot.ts

@@ -20,6 +20,7 @@ import { mainRouter } from '@/router.js';
 import { initializeSw } from '@/scripts/initialize-sw.js';
 import { deckStore } from '@/ui/deck/deck-store.js';
 import { emojiPicker } from '@/scripts/emoji-picker.js';
+import { SnowfallEffect } from '@/scripts/snowfall-effect.js';
 
 export async function mainBoot() {
 	const { isClientUpdated } = await common(() => createApp(
@@ -75,6 +76,13 @@ export async function mainBoot() {
 		},
 	};
 
+	if (defaultStore.state.enableSeasonalScreenEffect) {
+		const month = new Date().getMonth() + 1;
+		if (month === 12 || month === 1) {
+			new SnowfallEffect().render();
+		}
+	}
+
 	if ($i) {
 		// only add post shortcuts if logged in
 		hotkeys['p|n'] = post;