fix: synchronize runtime locales and harden online updates

Translate UI, scheduler, validation, preload and maintenance messages dynamically, and propagate locale changes between workers. Harden update checks, downloads and terminal states, verify Debian pnpm, and ignore generated test artifacts.

back/shared/languageSync.ts

@@ -0,0 +1,32 @@
+import cluster from 'cluster';
+import { setLang, systemLang } from './i18n';
+
+function languageMessage(
+  message: unknown,
+): message is { type: string; lang: string } {
+  const value = message as { type?: string; lang?: string } | null;
+  return (
+    value?.type === 'language-changed' && ['zh', 'en'].includes(value.lang!)
+  );
+}
+
+// Each worker owns a translation cache. Relay saved settings to live workers;
+// a replacement worker restores the persisted language before serving requests.
+export async function initializeLanguageSync() {
+  if (cluster.isPrimary) {
+    cluster.on('message', (_worker, message) => {
+      if (!languageMessage(message)) return;
+      setLang(message.lang, false);
+      for (const worker of Object.values(cluster.workers || {})) {
+        if (worker?.isConnected()) worker.send(message, () => {});
+      }
+    });
+    return;
+  } else {
+    process.on('message', (message) => {
+      if (languageMessage(message)) setLang(message.lang, false);
+    });
+  }
+  const { shareStore } = await import('./store');
+  setLang((await shareStore.getLang()) || systemLang(), false);
+}