core&ui: trigger i18n update event

packages/hydrooj/src/lib/i18n.ts

@@ -7,6 +7,11 @@ declare module '../context' {
         i18n: I18nService;
     }
 }
+declare module '../service/bus' {
+    interface EventMap {
+        'app/i18n/update': (lang: string) => void;
+    }
+}
 declare global {
     interface String {
         translate: (...languages: string[]) => string;
@@ -22,6 +27,7 @@ class I18nService extends Service {
         this.ctx.effect(() => {
             translations[lang] ||= [];
             translations[lang].unshift(content);
+            this.ctx.emit('app/i18n/update', lang);
             return () => {
                 translations[lang] = translations[lang].filter((i) => i !== content);
             };