refactor: use plaintext Gitea URL instead of XOR+Base64 scramble

- Gitea URL hardcoded as GITEA_API constant (no more release-notes discovery)
- Removed parseUpdateSource / unscramble / SCRAMBLE_KEY
- Release notes no longer need update-source comment
- version 1.9.4 -> 1.9.5 (code 33 -> 34)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "com.a2i.forwarder"
         minSdk = 34
         targetSdk = 36
-        versionCode = 30
-        versionName = "1.9.1"
+        versionCode = 34
+        versionName = "1.9.5"
     }
 
     signingConfigs {

app/src/main/java/com/a2i/forwarder/core/UpdateChecker.kt

@@ -45,6 +45,7 @@ class UpdateChecker(private val context: Context) {
     val updateInfo = MutableStateFlow<UpdateInfo?>(null)
     val downloading = MutableStateFlow(false)
     val downloadProgress = MutableStateFlow(0)
+    val downloadSource = MutableStateFlow<String?>(null)  // "Gitea" / "GitHub" / null
     val lastError = MutableStateFlow<String?>(null)
     private var lastNotifiedVersion: String? = null  // 记录已推送的版本，避免重复通知
 
@@ -69,19 +70,15 @@ class UpdateChecker(private val context: Context) {
             val now = System.currentTimeMillis()
             if (throttle && now - settings.lastUpdateCheckTime.value < CHECK_INTERVAL_MS) return@runCatching updateInfo.value
 
-            // 先查 GitHub（公开默认源），从其 release notes 动态发现额外源（如自建 Gitea），取最高版本
+            // 双源查询：Gitea（国内优先）+ GitHub（备用），取最高版本
             // 同版本时 Gitea 优先（国内可达，GitHub 可能被墙导致下载失败）
             val infos = mutableListOf<UpdateInfo>()
             var ghInfo: UpdateInfo? = null
             var giteaInfo: UpdateInfo? = null
-            val gh = runCatching { fetchRelease(GITHUB_API) }.getOrNull()
-            if (gh != null) {
-                ghInfo = gh
-                giteaInfo = parseUpdateSource(gh.releaseNotes)?.let { runCatching { fetchRelease(it) }.getOrNull() }
-                // Gitea 放前面，同版本时优先用它下载（国内可达）
+            giteaInfo = runCatching { fetchRelease(GITEA_API) }.getOrNull()
             if (giteaInfo != null) infos.add(giteaInfo)
-                infos.add(gh)
-            }
+            ghInfo = runCatching { fetchRelease(GITHUB_API) }.getOrNull()
+            if (ghInfo != null) infos.add(ghInfo)
             settings.setLastUpdateCheck(now)
             if (infos.isEmpty()) {
                 lastError.value = "所有更新源不可达"
@@ -184,33 +181,49 @@ class UpdateChecker(private val context: Context) {
     suspend fun download(info: UpdateInfo): File? = withContext(Dispatchers.IO) {
         downloading.value = true
         downloadProgress.value = 0
+        downloadSource.value = null
         lastError.value = null
-        // 主 URL 失败时自动尝试备选 URL
-        val urls = listOf(info.apkUrl) + (info.fallbackUrl?.let { listOf(it) } ?: emptyList())
-        for ((idx, url) in urls.withIndex()) {
-            if (idx > 0) downloadProgress.value = 0  // 重试时重置进度
-            val file = tryDownload(url, info.latestVersion)
+        // 主 URL (Gitea) 失败时自动尝试备选 URL (GitHub)
+        val sources = listOf(
+            info.apkUrl to sourceLabel(info.apkUrl),
+        ) + (info.fallbackUrl?.let { listOf(it to sourceLabel(it)) } ?: emptyList())
+        for ((idx, pair) in sources.withIndex()) {
+            val (url, label) = pair
+            if (idx > 0) { downloadProgress.value = 0; downloadSource.value = null }
+            downloadSource.value = label
+            val file = tryDownload(url, info.latestVersion, info.apkSize)
             if (file != null) {
                 downloading.value = false
+                downloadSource.value = null
                 return@withContext file
             }
         }
         downloading.value = false
+        downloadSource.value = null
         null
     }
 
-    private suspend fun tryDownload(url: String, version: String): File? {
+    private fun sourceLabel(url: String): String =
+        if (url.contains("songer.eu.org") || url.contains("sunlunfan")) "Gitea" else "GitHub"
+
+    private suspend fun tryDownload(url: String, version: String, expectedSize: Long): File? {
+        // 专用下载 client：更长超时（120s），避免大文件慢网超时截断
+        val dlClient = OkHttpClient.Builder()
+            .connectTimeout(15, TimeUnit.SECONDS)
+            .readTimeout(120, TimeUnit.SECONDS)
+            .retryOnConnectionFailure(true)
+            .build()
         return try {
             val req = Request.Builder().url(url).get().build()
-            http.newCall(req).execute().use { res ->
-                if (!res.isSuccessful) { lastError.value = "HTTP ${res.code}"; return@tryDownload null }
-                val body = res.body ?: run { lastError.value = "空响应"; return@tryDownload null }
+            dlClient.newCall(req).execute().use { res ->
+                if (!res.isSuccessful) { lastError.value = "HTTP ${res.code}"; return null }
+                val body = res.body ?: run { lastError.value = "空响应"; return null }
                 val total = body.contentLength()
                 val dir = context.getExternalFilesDir(null) ?: context.cacheDir
                 val target = File(dir, "gotmsg-${version}.apk")
                 target.outputStream().use { sink ->
                     val input = body.byteStream()
-                    val buf = ByteArray(8 * 1024)
+                    val buf = ByteArray(64 * 1024)  // 64KB buffer 提升大文件速度
                     var read = 0L
                     while (true) {
                         val n = input.read(buf)
@@ -220,6 +233,19 @@ class UpdateChecker(private val context: Context) {
                         if (total > 0) downloadProgress.value = (read * 100 / total).toInt()
                     }
                 }
+                // 校验文件大小：Content-Length 或 release 声明的大小
+                val actualSize = target.length()
+                val refSize = if (total > 0) total else expectedSize
+                if (refSize > 0 && actualSize < refSize) {
+                    lastError.value = "文件不完整（${actualSize}/${refSize} 字节），请重试"
+                    target.delete()
+                    return null
+                }
+                if (actualSize < 1_000_000) {
+                    lastError.value = "文件过小，可能下载了错误页面"
+                    target.delete()
+                    return null
+                }
                 downloadProgress.value = 100
                 target
             }
@@ -273,26 +299,10 @@ class UpdateChecker(private val context: Context) {
         return false
     }
 
-    /** 从 release notes 的 HTML 注释里解析额外更新源（加扰编码，兼容 Base64/明文）。 */
-    private fun parseUpdateSource(body: String): String? {
-        val raw = Regex("""update-source:\s*(\S+)""").find(body)?.groupValues?.getOrNull(1) ?: return null
-        // 加扰格式：Base64(反转(XOR(明文, key)))。尝试完整解扰，失败则依次尝试 Base64/明文。
-        val b64 = runCatching { java.util.Base64.getDecoder().decode(raw) }.getOrNull() ?: return raw
-        val unscrambled = unscramble(b64)
-        return unscrambled ?: runCatching { String(b64, Charsets.UTF_8) }.getOrNull() ?: raw
-    }
-
-    /** 解扰：反转字节 → XOR 每字节 → UTF-8 字符串。 */
-    private fun unscramble(data: ByteArray): String? = runCatching {
-        val key = SCRAMBLE_KEY
-        val reversed = data.reversedArray()
-        String(ByteArray(reversed.size) { i -> ((reversed[i].toInt() and 0xFF) xor (key[i % key.size].toInt() and 0xFF)).toByte() }, Charsets.UTF_8)
-    }.getOrNull()
-
     companion object {
         const val GITHUB_API = "https://api.github.com/repos/lsxf/a2i/releases/latest"
+        const val GITEA_API = "https://gitea.songer.eu.org/api/v1/repos/song/a2i/releases/latest"
         const val CHECK_INTERVAL_MS = 24L * 60 * 60 * 1000
-        private val SCRAMBLE_KEY = byteArrayOf(0x4B, 0x6F, 0x72, 0x6E)  // "Korn"
     }
 
     fun formatSize(bytes: Long): String {

app/src/main/java/com/a2i/forwarder/ui/screens/UpdateDialog.kt

@@ -37,6 +37,7 @@ fun UpdateDialog(info: UpdateInfo, onDismiss: () -> Unit) {
     val app = A2iApp.instance
     val downloading by app.updateChecker.downloading.collectAsState()
     val progress by app.updateChecker.downloadProgress.collectAsState()
+    val downloadSource by app.updateChecker.downloadSource.collectAsState()
     var downloadedFile by remember { mutableStateOf<File?>(null) }
 
     AlertDialog(
@@ -70,7 +71,7 @@ fun UpdateDialog(info: UpdateInfo, onDismiss: () -> Unit) {
                     )
                     Spacer(Modifier.size(4.dp))
                     Text(
-                        "正在下载更新…",
+                        "正在下载更新…${downloadSource?.let { "（来自 $it）" } ?: ""}",
                         style = MaterialTheme.typography.bodySmall,
                         color = MaterialTheme.colorScheme.onSurfaceVariant,
                     )