Added a make android-studio target that wraps ./run-image.sh bash build-image/prepare-android-project.sh --host-paths, and updated the README (Layout's Makefile-target list, "5.2. Building natively in Android Studio", and "5.3. Testing cycles") to reference it — including a note that it must be re-run after make clean specifically, since that's what just bit you. Run make android-studio now to fix the build.

Makefile

@@ -14,7 +14,7 @@ ASSETS_DIR  := res/assets/ss_ee
 BUILD_DIR   := build
 ARCH        := $(shell uname -m)
 
-.PHONY: all dist build-image engine assets package apk clean
+.PHONY: all dist build-image engine assets package apk android-studio clean
 
 all: dist
 
@@ -108,6 +108,21 @@ apk:
 		./run-image.sh bash build-image/build-apk.sh; \
 	fi
 
+# Stages a scratch, patched copy of engine/ and android/gl4es-src/, plus
+# the Android SDL2/SDL2_mixer/fluidsynth-lite/openxr prebuilts, with
+# host-resolvable paths (writes android/engine.properties) so Android
+# Studio can compile and deploy android/ natively - see README's "5.2.
+# Building natively in Android Studio". `make apk` doesn't need this; it
+# stages the same things itself inside the build-image. Re-run after
+# `make clean` (which deletes android/engine.properties) or after
+# changing engine/, android/engine-patches/, android/gl4es-src/,
+# android/gl4es-patches/, or the prebuilt-library versions in
+# build-image/Dockerfile - Android Studio's own Gradle build already
+# does this automatically via its stageEngine task, so this is mainly
+# useful for first-time setup or confirming staging succeeded on its own.
+android-studio:
+	./run-image.sh bash build-image/prepare-android-project.sh --host-paths
+
 clean:
 	rm -rf "$(DIST_DIR)" "$(BUILD_DIR)" "$(ENGINE_OUT)" \
 		engine/build_ext engine/CMakeCache.txt engine/CMakeFiles \