fix(build): resolve Gradle and manifest issues for TorrentEngine

- Remove deprecated android.enableBuildCache from gradle.properties
- Downgrade Kotlin from 2.1.0 to 1.9.24 for Room compatibility
- Add tools namespace to AndroidManifest.xml
- Restore LibTorrent4j to 2.1.0-28 (verified available version)

Known issue: TorrentEngine.kt needs API updates for LibTorrent4j 2.1.x
See compilation errors related to SessionParams, popAlerts, TorrentInfo constructor

android/gradle.properties

@@ -16,5 +16,5 @@ kotlin.incremental=true
 kotlin.incremental.usePreciseJavaTracking=true
 
 # Build optimization
-android.enableBuildCache=true
+# android.enableBuildCache=true  # Deprecated in AGP 7.0+, use org.gradle.caching instead
 org.gradle.vfs.watch=false

android/settings.gradle.kts

@@ -28,7 +28,7 @@ plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
     id("com.android.application") version "8.7.3" apply false
     id("com.android.library") version "8.7.3" apply false
-    id("org.jetbrains.kotlin.android") version "2.1.0" apply false
+    id("org.jetbrains.kotlin.android") version "1.9.24" apply false
 }
 
 include(":app")

android/torrentengine/build.gradle.kts

@@ -62,6 +62,7 @@ dependencies {
     implementation("com.google.code.gson:gson:2.11.0")
 
     // LibTorrent4j - Java bindings for libtorrent
+    // Using main package which includes native libraries
     implementation("org.libtorrent4j:libtorrent4j:2.1.0-28")
     implementation("org.libtorrent4j:libtorrent4j-android-arm64:2.1.0-28")
     implementation("org.libtorrent4j:libtorrent4j-android-arm:2.1.0-28")

android/torrentengine/src/main/AndroidManifest.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
 
     <!-- Permissions for torrent engine -->
     <uses-permission android:name="android.permission.INTERNET" />