Add APK build target

ober

ebc113ff71b095d885f458e1dc21c45c87831d73

diff --git a/Makefile b/Makefile
index 69b3d24..87aa2a8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,20 @@
 JERBOA ?= jerboa
 BUILD_DIR ?= build/counter
 EXAMPLE ?= examples/counter/app.ss
+JAVA_HOME ?= /opt/homebrew/opt/openjdk@21/libexec/openjdk.jdk/Contents/Home
+ANDROID_HOME ?= $(HOME)/Library/Android/sdk
+ANDROID_SDK_ROOT ?= $(ANDROID_HOME)
+export JAVA_HOME
+export ANDROID_HOME
+export ANDROID_SDK_ROOT
+export PATH := $(JAVA_HOME)/bin:/opt/homebrew/bin:$(PATH)
 
-.PHONY: help clean generate test
+.PHONY: help clean generate test apk
 
 help:
 	@echo "Targets:"
 	@echo "  generate  Generate the counter Android project"
+	@echo "  apk       Generate and build the debug APK"
 	@echo "  test      Run the local generator smoke test"
 	@echo "  clean     Remove generated output"
 
@@ -16,6 +24,9 @@ clean:
 generate:
 	$(JERBOA) jandroid.ss generate $(EXAMPLE) $(BUILD_DIR)
 
+apk: generate
+	gradle --no-daemon -p $(BUILD_DIR) assembleDebug
+
 test: clean generate
 	test -f $(BUILD_DIR)/settings.gradle.kts
 	test -f $(BUILD_DIR)/app/build.gradle.kts