Fix missing-assets detection race, 16 KB page alignment, and Android audio backend

- QuestShockActivity now actually blocks the native engine from starting
  when game data is missing, closing three gaps found via on-device
  testing: super.onCreate() must run unconditionally first (Android
  throws SuperNotCalledException otherwise); SDLActivity.mBrokenLibraries
  is now set provisionally before the storage-permission check, since
  onWindowFocusChanged() closing the permission dialog could otherwise
  start the engine before the async onRequestPermissionsResult() callback
  ran; and a new GameSurface (SDLSurface subclass) closes the actual gap
  that let the init_popups NULL-deref crash through even with
  mBrokenLibraries set - SDLSurface.surfaceChanged() starts the native
  thread directly without ever checking that flag.
- Force Android to use SDL2's openslES audio backend instead of AAudio
  (android/engine-patches/05-android-audio-driver.patch): AAudio only
  allows one open playback device at a time, but the engine opens two
  (cutscene audio via SDL_OpenAudioDevice, SFX/MIDI via Mix_OpenAudio),
  hitting an assertion failure on real hardware.
- Add 16 KB ELF page-size alignment (-Wl,-z,max-page-size=16384) to every
  Android shared library - the four prebuilts (SDL2, SDL2_mixer,
  fluidsynth-lite, gl4es, in build-image/Dockerfile) and the engine's own
  libmain.so (build.gradle) - matching Google's Play Store requirement
  for Android 15+ and clearing Android Studio's compatibility warning.
- Add a stageEngine Gradle task that automatically re-stages the patched
  engine/ copy and prebuilt libraries before any Android Studio build
  (hooked into preBuild, with proper up-to-date checking), so source/
  patch changes can't silently go stale in the build/android-engine
  scratch copy - previously a manual, easy-to-forget step. Skips
  automatically inside the build-image container so make apk/CI are
  unaffected.

build-image/Dockerfile

@@ -46,6 +46,13 @@ ARG ANDROID_COMPILE_SDK_VERSION=34
 ARG ANDROID_BUILD_TOOLS_VERSION=34.0.0
 ARG ANDROID_NDK_VERSION=26.1.10909125
 ARG ANDROID_CMAKE_VERSION=3.22.1
+# NDK 26 doesn't yet default to 16 KB-aligned ELF LOAD segments (that only
+# became automatic in NDK 28+) - Google requires this for Play Store
+# submissions targeting Android 15+ as of Nov 2025, and it's cheap/harmless
+# to do regardless of Play Store status. Passed to every Android shared-lib
+# CMake configure below, and to the engine's own build via
+# android/app/build.gradle's externalNativeBuild.cmake.arguments.
+ARG ANDROID_16KB_LDFLAGS="-Wl,-z,max-page-size=16384"
 # GL4ES (https://github.com/ptitSeb/gl4es) - translates the engine's
 # desktop-style immediate-mode OpenGL calls into real GLES/EGL calls, so
 # engine/src/MacSrc/OpenGL.cc needs no immediate-mode rewrite on Android.
@@ -182,6 +189,7 @@ RUN curl -sSLO "https://www.libsdl.org/release/SDL2-${ANDROID_SDL2_VERSION}.tar.
         -DANDROID_ABI="${ANDROID_ABI}" -DANDROID_PLATFORM="android-${ANDROID_PLATFORM_VERSION}" \
         -DCMAKE_INSTALL_PREFIX=/opt/prebuilt/android/sdl2 -DBUILD_SHARED_LIBS=ON \
         -DSDL_STATIC=OFF \
+        -DCMAKE_SHARED_LINKER_FLAGS="${ANDROID_16KB_LDFLAGS}" \
     && cmake --build build-sdl2-android -j"$(nproc)" \
     && cmake --install build-sdl2-android \
     && rm -rf "SDL2-${ANDROID_SDL2_VERSION}" "SDL2-${ANDROID_SDL2_VERSION}.tar.gz" build-sdl2-android
@@ -207,6 +215,7 @@ RUN curl -sSLO "https://www.libsdl.org/projects/SDL_mixer/release/SDL2_mixer-${A
         -DSDL2MIXER_FLAC=OFF -DSDL2MIXER_GME=OFF -DSDL2MIXER_MOD=OFF \
         -DSDL2MIXER_MP3=OFF -DSDL2MIXER_MIDI=OFF -DSDL2MIXER_OPUS=OFF -DSDL2MIXER_VORBIS=OFF \
         -DSDL2MIXER_WAVPACK=OFF \
+        -DCMAKE_SHARED_LINKER_FLAGS="${ANDROID_16KB_LDFLAGS}" \
     && cmake --build build-sdl2mixer-android -j"$(nproc)" \
     && cmake --install build-sdl2mixer-android \
     && rm -rf "SDL2_mixer-${ANDROID_SDL2_MIXER_VERSION}" "SDL2_mixer-${ANDROID_SDL2_MIXER_VERSION}.tar.gz" build-sdl2mixer-android
@@ -222,6 +231,7 @@ RUN git clone https://github.com/EtherTyper/fluidsynth-lite.git fluidsynth-lite-
     && cmake -S fluidsynth-lite-android -B build-fluidsynth-android \
         -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK_TOOLCHAIN}" \
         -DANDROID_ABI="${ANDROID_ABI}" -DANDROID_PLATFORM="android-${ANDROID_PLATFORM_VERSION}" \
+        -DCMAKE_SHARED_LINKER_FLAGS="${ANDROID_16KB_LDFLAGS}" \
     && cmake --build build-fluidsynth-android -j"$(nproc)" \
     && mkdir -p /opt/prebuilt/android/fluidsynth-lite/lib /opt/prebuilt/android/fluidsynth-lite/include \
     && cp -a build-fluidsynth-android/src/libfluidsynth.so* /opt/prebuilt/android/fluidsynth-lite/lib/ \
@@ -254,6 +264,7 @@ RUN git clone --branch "v${ANDROID_GL4ES_VERSION}" --depth 1 \
         -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK_TOOLCHAIN}" \
         -DANDROID_ABI="${ANDROID_ABI}" -DANDROID_PLATFORM="android-${ANDROID_PLATFORM_VERSION}" \
         -DANDROID=ON -DUSE_ANDROID_LOG=ON -DSTATICLIB=OFF \
+        -DCMAKE_SHARED_LINKER_FLAGS="${ANDROID_16KB_LDFLAGS}" \
     && cmake --build build-gl4es-android -j"$(nproc)" \
     && mkdir -p /opt/prebuilt/android/gl4es/lib /opt/prebuilt/android/gl4es/include \
     && cp -a gl4es-android/lib/libGL.so.1 /opt/prebuilt/android/gl4es/lib/libGL.so \