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.

android/app/build.gradle

@@ -1,15 +1,31 @@
 apply plugin: 'com.android.application'
 
-// Path to the (patched, at build time - see build-apk.sh and
-// ../engine-patches/) scratch copy of engine/, written by build-apk.sh
-// since it's only known at build time, not something a checked-in
-// build.gradle can hardcode.
+// Paths written by build-image/prepare-android-project.sh (called by
+// build-apk.sh, or standalone with --host-paths to prep for a native
+// build in Android Studio - see README) since they're only known at
+// prep/build time, not something a checked-in build.gradle can hardcode.
+// engineDir is the scratch, patched copy of engine/; prebuiltDir is the
+// Android SDL2/SDL2_mixer/fluidsynth-lite/gl4es prebuilts - both point
+// into this container's own paths for build-apk.sh's own gradlew call,
+// or host-resolvable paths (plus a host-side export of prebuiltDir, since
+// /opt/prebuilt/android only exists in the image) when prepared with
+// --host-paths for Android Studio.
 def engineProps = new Properties()
 file("${projectDir}/../engine.properties").withInputStream { engineProps.load(it) }
 def engineDir = engineProps.getProperty('engineDir')
 if (engineDir == null) {
-    throw new GradleException("android/engine.properties is missing 'engineDir' - run via build-apk.sh, not gradlew directly")
+    throw new GradleException("android/engine.properties is missing 'engineDir' - run via build-apk.sh or prepare-android-project.sh, not gradlew directly")
 }
+def prebuiltDir = engineProps.getProperty('prebuiltDir')
+if (prebuiltDir == null) {
+    throw new GradleException("android/engine.properties is missing 'prebuiltDir' - run via build-apk.sh or prepare-android-project.sh, not gradlew directly")
+}
+
+// Set by build-apk.sh (see build-image/version.sh, shared with the
+// desktop tarball's versioning) via -PquestshockVersionName/Code. Default
+// here only covers a direct, unsupported `gradlew` invocation.
+def questshockVersionName = project.hasProperty('questshockVersionName') ? project.property('questshockVersionName') : '0.0.0-dev'
+def questshockVersionCode = project.hasProperty('questshockVersionCode') ? project.property('questshockVersionCode').toInteger() : 1
 
 android {
     namespace "de.ladkau.questshock"
@@ -31,8 +47,8 @@ android {
         // targets - not just whatever's the current API level today.
         minSdkVersion 24
         targetSdkVersion 29
-        versionCode 1
-        versionName "1.0"
+        versionCode questshockVersionCode
+        versionName questshockVersionName
 
         externalNativeBuild {
             cmake {
@@ -42,8 +58,9 @@ android {
                 // config, unlike the desktop build's older bundled copy);
                 // SDL2_mixer and FluidSynth via the same build_ext/ BUNDLED
                 // convention the desktop build already uses (populated in the
-                // scratch engine copy by build-apk.sh from
-                // /opt/prebuilt/android/*).
+                // scratch engine copy by prepare-android-project.sh from
+                // prebuiltDir). ANDROID_PREBUILT_DIR is also read directly by
+                // android/engine-patches/02-android-opengl-es.patch, for gl4es.
                 // The CMAKE_FIND_ROOT_PATH* overrides below are needed
                 // because the NDK toolchain file restricts find_package/
                 // find_path/find_library to its own sysroot by default,
@@ -51,8 +68,9 @@ android {
                 // build-image/Dockerfile's SDL2_mixer build, which hit the
                 // exact same thing).
                 arguments "-DENABLE_SDL2=ON", "-DENABLE_SOUND=BUNDLED", "-DENABLE_FLUIDSYNTH=BUNDLED", \
-                    "-DCMAKE_PREFIX_PATH=/opt/prebuilt/android/sdl2", \
-                    "-DCMAKE_FIND_ROOT_PATH=/opt/prebuilt/android/sdl2", \
+                    "-DANDROID_PREBUILT_DIR=${prebuiltDir}", \
+                    "-DCMAKE_PREFIX_PATH=${prebuiltDir}/sdl2", \
+                    "-DCMAKE_FIND_ROOT_PATH=${prebuiltDir}/sdl2", \
                     "-DCMAKE_FIND_ROOT_PATH_MODE_PACKAGE=BOTH", \
                     "-DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=BOTH", \
                     "-DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=BOTH", \

android/app/src/main/java/de/ladkau/questshock/QuestShockActivity.java

@@ -1,6 +1,7 @@
 package de.ladkau.questshock;
 
 import android.Manifest;
+import android.app.AlertDialog;
 import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
 import android.os.Bundle;
@@ -96,6 +97,18 @@ public class QuestShockActivity extends SDLActivity {
             copyAssetFile("GET_ASSETS_QUEST.txt", marker);
         }
 
+        // Shockolate's engine/ is never patched to check this itself (see the
+        // class doc above) - it just does plain fopen("res/data/...", ...)
+        // and, on a fresh install with no game data copied in yet, that
+        // fails deep inside startup (init_popups(), which doesn't NULL-check
+        // the load) as a hard native crash instead of a message. Catch the
+        // missing-data case here instead, before super.onCreate() ever
+        // starts Shockolate's native main().
+        if (!isNonEmptyDir(new File(gameDir, "res/data")) || !isNonEmptyDir(new File(gameDir, "res/sound"))) {
+            showMissingAssetsDialog();
+            return;
+        }
+
         // chdir() is process-wide, not per-thread - already in effect for
         // every thread (including the one that will run Shockolate's own
         // SDL_main) by the time super.onCreate() below starts it.
@@ -104,6 +117,40 @@ public class QuestShockActivity extends SDLActivity {
         super.onCreate(mSavedInstanceState);
     }
 
+    private static boolean isNonEmptyDir(File dir) {
+        String[] entries = dir.list();
+        return entries != null && entries.length > 0;
+    }
+
+    // Same single-button, non-cancelable pattern as SDLActivity's own
+    // "broken libraries" dialog (org/libsdl/app/SDLActivity.java) - there's
+    // no game to start without this data, so the only way forward is to
+    // close, copy the assets, and relaunch. Message text mirrors
+    // res/assets/GET_ASSETS_QUEST.txt (also extracted to GAME_DIR) so the
+    // user isn't sent hunting for a second file just to read it the first
+    // time - it points back there at the end in case they need it again.
+    private void showMissingAssetsDialog() {
+        new AlertDialog.Builder(this)
+            .setTitle("Game data missing")
+            .setMessage("This app does not include System Shock's game data - it's "
+                + "copyrighted, proprietary content that can't be redistributed. To "
+                + "play, you need to own a copy of System Shock: Enhanced Edition (e.g. "
+                + "from gog.com), installed (on Windows, or via Wine/Proton on Linux).\n\n"
+                + "Using SideQuest (or any MTP file browser) with your Quest connected, "
+                + "copy its res/data/ and res/sound/ folders directly into:\n"
+                + GAME_DIR + "/res/data/\n"
+                + GAME_DIR + "/res/sound/\n"
+                + "They already contain everything needed, in the right layout - no "
+                + "merging or extraction required.\n\n"
+                + "Then relaunch.\n\n"
+                + "(These instructions are also in GET_ASSETS_QUEST.txt in the "
+                + "questshock folder on this device, if you need to read them again.)")
+            .setCancelable(false)
+            .setPositiveButton("Exit", (dialog, which) -> finish())
+            .create()
+            .show();
+    }
+
     private void copyAssetFile(String assetPath, File dest) {
         if (dest.exists()) {
             return;