ci: optimize RAM usage and add CI/CD pipelines

- Reduce Gradle RAM from 4GB to 2GB with optimizations
- Add GitLab CI/CD with separate jobs for TorrentEngine and APK
- Add GitHub Actions workflow as alternative
- Enable parallel builds and caching
- Configure automated artifact uploads
- Add comprehensive CI/CD documentation

android/gradle.properties

@@ -1,3 +1,20 @@
-org.gradle.jvmargs=-Xmx4G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
+# Gradle JVM settings - optimized for limited RAM
+org.gradle.jvmargs=-Xmx2G -XX:MaxMetaspaceSize=1G -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
+org.gradle.daemon=true
+org.gradle.parallel=true
+org.gradle.caching=true
+org.gradle.configureondemand=true
+
+# Android settings
 android.useAndroidX=true
 android.enableJetifier=true
+android.enableR8.fullMode=false
+
+# Kotlin settings
+kotlin.daemon.jvmargs=-Xmx1G -XX:MaxMetaspaceSize=512m
+kotlin.incremental=true
+kotlin.incremental.usePreciseJavaTracking=true
+
+# Build optimization
+android.enableBuildCache=true
+org.gradle.vfs.watch=false