Android port

Android.mk builds libsetcore.so from the same C99 sources used by MCU and desktop builds. setcore_jni.c contains only JNI marshalling; protocol rules remain in the core. Add the Kotlin directory as an Android source directory and include this Android.mk from the application NDK build.

The JNI streaming parser returns fixed 15-byte records SEQ | FLAGS | CAN_ID_LE | DLC | DATA[8]. Dynamic allocation is confined to the Android adapter; the portable core remains allocation free.