feat(desktop): add offline cache and verified app updates

Clean release notes in Android and desktop update dialogs. Persist downloaded audio and offline playback events per server and user; add desktop update checks, checksum verification and installer launch.

apps/mobile/src/ui/UpdateDialog.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useSyncExternalStore } from 'react';
+import { releaseNotesText } from '@pipu/core';
 import { useTranslation } from 'react-i18next';
 import { AppState, Modal, Pressable, ScrollView, Text, View } from 'react-native';
 
@@ -10,7 +11,6 @@ import { Button } from './kit';
 export function useUpdateState() {
   return useSyncExternalStore(updater.subscribe, () => updater.state);
 }
-
 /** Проверяет обновления при запуске и возврате в приложение; показывает диалог с «Что нового». */
 export function UpdateDialog() {
   const colors = useColors();
@@ -32,6 +32,7 @@ export function UpdateDialog() {
 
   const { release, required } = st;
   const busy = st.status === 'downloading' || st.status === 'verifying';
+  const notes = releaseNotesText(release.notes_md);
   const action = () => void updater.downloadAndInstall(session, server ?? '');
 
   return (
@@ -57,9 +58,9 @@ export function UpdateDialog() {
             {t('mobile.update_title', { version: release.version })}
           </Text>
           {required && <Text style={{ color: colors.danger }}>{t('mobile.update_required')}</Text>}
-          {release.notes_md.trim() !== '' && (
-            <ScrollView style={{ maxHeight: 240 }}>
-              <Text style={{ color: colors.text2, lineHeight: 20 }}>{plainNotes(release.notes_md)}</Text>
+          {notes !== '' && (
+            <ScrollView style={{ maxHeight: 240, flexShrink: 1 }}>
+              <Text style={{ color: colors.text2, lineHeight: 20 }}>{notes}</Text>
             </ScrollView>
           )}
           <Text style={{ color: colors.text3, fontSize: 12 }}>
@@ -115,13 +116,3 @@ export function UpdateDialog() {
     </Modal>
   );
 }
-
-/** Заметки релиза — Markdown; в диалоге показываем текстом без разметки заголовков и выделения. */
-function plainNotes(md: string): string {
-  return md
-    .replace(/^#{1,6}\s*/gm, '')
-    .replace(/\*\*(.+?)\*\*/g, '$1')
-    .replace(/^\s*[-*]\s+/gm, '• ')
-    .replace(/\[(.+?)\]\(.+?\)/g, '$1')
-    .trim();
-}