Fix Quest launch crashes, version the APK like the tarball, and support native builds in Android Studio

- patchelf gl4es's embedded SONAME to libGL.so so AGP's jniLibs packaging
  (which drops any file not literally named "*.so") and the dynamic
  linker's NEEDED-entry resolution (by embedded SONAME, not filename)
  finally agree - fixes the "library \"libGL.so.1\" not found" crash seen
  on real Quest hardware.
- QuestShockActivity now checks that res/data and res/sound exist before
  starting the native engine, showing an explanatory dialog instead of
  crashing on init_popups' unchecked NULL resource load when a fresh
  install has no game data copied in yet.
- dist/questshock-<version>-android-arm64.apk is now versioned from the
  same git-tag-or-dev-placeholder scheme as the desktop tarball
  (build-image/version.sh, shared by both via the Makefile and
  build-apk.sh).
- build-image/prepare-android-project.sh (prep logic extracted out of
  build-apk.sh) can now stage android/ for a native build directly in
  Android Studio (--host-paths), exporting the prebuilt SDL2/SDL2_mixer/
  fluidsynth-lite/gl4es libraries and writing host-resolvable paths,
  instead of only ever building inside the Docker image.
- Corrected GET_ASSETS.txt/GET_ASSETS_QUEST.txt, which wrongly described
  merging res/pc/hd and res/pc/cdrom trees out of the raw installer's
  sshock.kpf - an already-installed copy's res/data res/sound can just
  be copied directly, with extract_assets.sh only needed from the raw
  installer.

Makefile

@@ -74,19 +74,7 @@ dist: engine assets
 # placeholder version, with a warning).
 package: engine
 	@git config --global --add safe.directory "$$(pwd)" 2>/dev/null || true
-	@V="$(VERSION)"; \
-	if [ -z "$$V" ]; then \
-		if TAG=$$(git describe --tags --exact-match --match 'v[0-9]*.[0-9]*.[0-9]*' 2>/dev/null); then \
-			V=$${TAG#v}; \
-		else \
-			V="0.0.0-dev+$$(git rev-parse --short HEAD)"; \
-			echo "WARNING: HEAD is not on a vX.Y.Z tag - building placeholder version $$V (push a tag to drive a real release version)" >&2; \
-		fi; \
-	fi; \
-	case "$$V" in \
-		[0-9]*.[0-9]*.[0-9]*) ;; \
-		*) echo "PREFLIGHT FAIL: VERSION '$$V' is not a semantic version (expected X.Y.Z, optionally with a -pre+meta suffix)" >&2; exit 1;; \
-	esac; \
+	@V="$$(VERSION="$(VERSION)" ./build-image/version.sh)"; \
 	PKG_NAME="shockolate-$$V-linux-$(ARCH)"; \
 	PKG_STAGE="$(BUILD_DIR)/package/$$PKG_NAME"; \
 	echo "Packaging $$PKG_NAME"; \