fix: 空渠道检测改用JSONObject.has + 移除gitignore误排除manifest

packages/client-android/android/app/src/main/java/dev/yuzu/gca/MainActivity.kt

@@ -147,16 +147,16 @@ class MainActivity : AppCompatActivity() {
 
         // 2. 解析
         appendLog("[2/4] 解析 manifest...")
-        if (!manifestJson.contains("\"android\"")) {
-            appendLog("  ℹ️ 该渠道暂无可用更新")
-            appendLog("=== $channel 渠道测试完成 ===")
-            return@withContext
-        }
         var manifestSha256 = ""
         var manifestApkUrl = ""
         var manifestTag = ""
         try {
             val json = JSONObject(manifestJson)
+            if (!json.getJSONObject("builds").has("android")) {
+                appendLog("  ℹ️ 该渠道暂无可用更新")
+                appendLog("=== $channel 渠道测试完成 ===")
+                return@withContext
+            }
             val android = json.getJSONObject("builds").getJSONObject("android")
             manifestSha256 = android.getString("sha256")
             manifestApkUrl = android.getString("url")