feat(mobile): self-update dialog with verified APK download and install (M5)

Checks the server for a newer release at most every 6 hours and on
demand in Profile, shows release notes, downloads the APK with progress,
verifies SHA-256 in 1 MB chunks and hands it to the system installer.
Updates below min_supported cannot be dismissed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/mobile/src/lib/update.ts

@@ -0,0 +1,207 @@
+import { unwrap, type AuthSession } from "@pipu/core";
+import type { components } from "@pipu/api-client";
+import Constants from "expo-constants";
+import * as FileSystem from "expo-file-system";
+import * as IntentLauncher from "expo-intent-launcher";
+import * as SecureStore from "expo-secure-store";
+import { sha256 } from "js-sha256";
+
+export type AndroidRelease = components["schemas"]["AndroidRelease"];
+
+/** Состояние самообновления (docs/mobile.md#самообновление). */
+export type UpdateState =
+  | { status: "idle" }
+  | { status: "checking" }
+  | { status: "latest" }
+  | {
+      status: "available";
+      release: AndroidRelease;
+      required: boolean;
+      dismissed: boolean;
+    }
+  | {
+      status: "downloading";
+      release: AndroidRelease;
+      required: boolean;
+      progress: number;
+    }
+  | { status: "verifying"; release: AndroidRelease; required: boolean }
+  | {
+      status: "ready";
+      release: AndroidRelease;
+      required: boolean;
+      file: string;
+    }
+  | {
+      status: "error";
+      release: AndroidRelease;
+      required: boolean;
+      error: "bad_checksum" | "failed";
+    };
+
+const CHECK_EVERY_MS = 6 * 60 * 60 * 1000;
+const CHECKED_KEY = "pipu.update.checked";
+const HASH_CHUNK = 1 << 20;
+const APK_MIME = "application/vnd.android.package-archive";
+
+export function installedVersionCode(): number {
+  return Number(
+    (Constants.expoConfig?.extra as { versionCode?: number } | undefined)
+      ?.versionCode ?? 0,
+  );
+}
+
+/** SHA-256 файла кусками по 1 МБ: целиком APK в память JS не читаем. */
+async function fileSha256(uri: string, size: number): Promise<string> {
+  const hash = sha256.create();
+  for (let pos = 0; pos < size; pos += HASH_CHUNK) {
+    const b64 = await FileSystem.readAsStringAsync(uri, {
+      encoding: FileSystem.EncodingType.Base64,
+      position: pos,
+      length: Math.min(HASH_CHUNK, size - pos),
+    });
+    const bin = atob(b64);
+    const bytes = new Uint8Array(bin.length);
+    for (let i = 0; i < bin.length; i++) bytes[i] = bin.charCodeAt(i);
+    hash.update(bytes);
+  }
+  return hash.hex();
+}
+
+class Updater {
+  private current: UpdateState = { status: "idle" };
+  private readonly listeners = new Set<() => void>();
+  private download: FileSystem.DownloadResumable | null = null;
+
+  get state(): UpdateState {
+    return this.current;
+  }
+
+  subscribe = (fn: () => void) => {
+    this.listeners.add(fn);
+    return () => this.listeners.delete(fn);
+  };
+
+  private set(s: UpdateState) {
+    this.current = s;
+    for (const fn of this.listeners) fn();
+  }
+
+  /** Проверка: автоматически — не чаще раза в 6 часов, вручную (профиль) — всегда. */
+  async check(session: AuthSession, manual = false): Promise<void> {
+    if (["checking", "downloading", "verifying"].includes(this.current.status))
+      return;
+    if (!manual) {
+      const last = Number((await SecureStore.getItemAsync(CHECKED_KEY)) ?? 0);
+      if (Date.now() - last < CHECK_EVERY_MS) return;
+    }
+    if (manual) this.set({ status: "checking" });
+    try {
+      const release = unwrap(
+        await session.client.GET("/api/v1/app/android/latest"),
+      );
+      await SecureStore.setItemAsync(CHECKED_KEY, String(Date.now()));
+      const installed = installedVersionCode();
+      if (release.version_code > installed) {
+        this.set({
+          status: "available",
+          release,
+          required: installed < release.min_supported,
+          dismissed: false,
+        });
+      } else {
+        this.set(manual ? { status: "latest" } : { status: "idle" });
+      }
+    } catch {
+      // Нет релиза или сервер без Gitea — молча; при ручной проверке показываем «последняя версия».
+      this.set(manual ? { status: "latest" } : { status: "idle" });
+    }
+  }
+
+  dismiss() {
+    const s = this.current;
+    if (s.status === "available" && !s.required)
+      this.set({ ...s, dismissed: true });
+    else if (s.status === "latest") this.set({ status: "idle" });
+  }
+
+  /** Скачивает APK с сервера (с Bearer), сверяет SHA-256 и запускает установщик. */
+  async downloadAndInstall(
+    session: AuthSession,
+    server: string,
+  ): Promise<void> {
+    const s = this.current;
+    if (
+      s.status !== "available" &&
+      s.status !== "error" &&
+      s.status !== "ready"
+    )
+      return;
+    const { release, required } = s;
+    if (s.status === "ready") return this.install(s.file);
+
+    // Любой запрос через client обновит access-токен, если он истёк.
+    await session.client
+      .GET("/api/v1/app/android/latest")
+      .catch(() => undefined);
+    const file = `${FileSystem.cacheDirectory}pipu-music-${release.version}.apk`;
+    this.set({ status: "downloading", release, required, progress: 0 });
+    try {
+      await FileSystem.deleteAsync(file, { idempotent: true });
+      this.download = FileSystem.createDownloadResumable(
+        server + release.download_url,
+        file,
+        { headers: { Authorization: `Bearer ${session.accessToken ?? ""}` } },
+        (p) => {
+          const total =
+            p.totalBytesExpectedToWrite > 0
+              ? p.totalBytesExpectedToWrite
+              : release.size;
+          this.set({
+            status: "downloading",
+            release,
+            required,
+            progress: total ? p.totalBytesWritten / total : 0,
+          });
+        },
+      );
+      const res = await this.download.downloadAsync();
+      this.download = null;
+      if (!res || res.status !== 200) throw new Error(`status ${res?.status}`);
+
+      this.set({ status: "verifying", release, required });
+      const info = await FileSystem.getInfoAsync(file);
+      const size = info.exists ? info.size : 0;
+      if ((await fileSha256(file, size)) !== release.sha256.toLowerCase()) {
+        await FileSystem.deleteAsync(file, { idempotent: true });
+        this.set({ status: "error", release, required, error: "bad_checksum" });
+        return;
+      }
+      this.set({ status: "ready", release, required, file });
+      await this.install(file);
+    } catch {
+      this.download = null;
+      this.set({ status: "error", release, required, error: "failed" });
+    }
+  }
+
+  private async install(file: string) {
+    const uri = await FileSystem.getContentUriAsync(file);
+    await IntentLauncher.startActivityAsync("android.intent.action.VIEW", {
+      data: uri,
+      type: APK_MIME,
+      flags: 1, // FLAG_GRANT_READ_URI_PERMISSION
+    });
+  }
+
+  /** Экран «Установка неизвестных приложений» для нашего пакета. */
+  async openInstallSettings() {
+    const pkg = Constants.expoConfig?.android?.package ?? "app.pipu.music";
+    await IntentLauncher.startActivityAsync(
+      "android.settings.MANAGE_UNKNOWN_APP_SOURCES",
+      { data: `package:${pkg}` },
+    );
+  }
+}
+
+export const updater = new Updater();