Fix i18n: auto-initialize locale on module load

The locale defaulted to 'en' until onMount ran initLocale(), causing
all server-side and initial client renders to show English even when
Russian was saved in localStorage.

Fix: read localStorage synchronously at module import time so t()
returns the correct locale from the first render.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/lib/i18n/index.ts

@@ -12,6 +12,19 @@ const translations: Record<Locale, Record<string, any>> = { en, ru };
 
 let currentLocale: Locale = 'en';
 
+// Auto-initialize from localStorage on module load (client-side)
+if (typeof localStorage !== 'undefined') {
+	const saved = localStorage.getItem('locale') as Locale | null;
+	if (saved && saved in translations) {
+		currentLocale = saved;
+	} else if (typeof navigator !== 'undefined') {
+		const lang = navigator.language.slice(0, 2);
+		if (lang in translations) {
+			currentLocale = lang as Locale;
+		}
+	}
+}
+
 export function getLocale(): Locale {
 	return currentLocale;
 }