Add androidNativeArm32 target across core modules (#503)

Enables 32-bit ARM Android Native builds alongside the existing arm64
target so vendor-specific backends can link native device libraries on
32-bit devices.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: michalharakal

skainet-compile/skainet-compile-core/build.gradle.kts

@@ -27,6 +27,10 @@ kotlin {
     linuxX64()
     linuxArm64()
 
+    // Android Native targets for vendor-specific backends linking native device libs.
+    androidNativeArm32()
+    androidNativeArm64()
+
     jvm()
 
     js {

skainet-lang/skainet-lang-core/build.gradle.kts

@@ -29,6 +29,10 @@ kotlin {
     linuxX64 ()
     linuxArm64 ()
 
+    // Android Native targets for vendor-specific backends linking native device libs.
+    androidNativeArm32()
+    androidNativeArm64()
+
     jvm()
 
     js {

skainet-lang/skainet-lang-ksp-annotations/build.gradle.kts

@@ -17,6 +17,11 @@ kotlin {
     linuxX64 ()
     linuxArm64 ()
 
+    // Android Native targets for vendor-specific backends linking directly against
+    // libneuralnetworks.so / libOpenCL.so / etc. (e.g. skainet-backend-nnapi).
+    androidNativeArm32()
+    androidNativeArm64()
+
     jvm()
 
     js {