diff --git a/scripts/ANDROID_TESTING.md b/scripts/ANDROID_TESTING.md
new file mode 100644
index 0000000..f5f1231
--- /dev/null
+++ b/scripts/ANDROID_TESTING.md
@@ -0,0 +1,228 @@
+# Android testing
+
+This directory contains lightweight Android test helpers for Ferrous Solitaire.
+They are intended to run against either a physical Android device or an emulator
+connected through `adb`. When no device is connected the smoke script can
+automatically launch an AVD for you.
+
+## Prerequisites
+
+- Android SDK and NDK installed.
+- `adb` available on `PATH`.
+- One device/emulator visible in `adb devices`, **or** at least one AVD created
+  (the script will launch one automatically if `LAUNCH_AVD=1`, which is the default).
+- If multiple devices are connected, set `ADB_SERIAL` to the target device serial.
+- Environment variables required by `scripts/build_android_apk.sh` when building:
+
+```sh
+export ANDROID_HOME=/path/to/android-sdk
+export ANDROID_NDK_HOME=/path/to/android-ndk
+export BUILD_TOOLS_VERSION=34.0.0
+export PLATFORM=android-34
+```
+
+## Smoke test
+
+From the workspace root (`Rusty_Solitaire/`):
+
+```sh
+scripts/android_smoke.sh
+```
+
+The smoke test first checks whether `adb` can see a ready device. If no device
+is connected and `LAUNCH_AVD=1` (default), it:
+
+1. locates the `emulator` binary under `ANDROID_HOME` or `PATH`,
+2. picks the first available AVD (or uses `AVD_NAME`),
+3. launches the emulator in the foreground (or headless with `AVD_HEADLESS=1`),
+4. waits for `sys.boot_completed=1` before proceeding,
+5. dismisses the lock screen so the screenshot shows the app.
+
+Once a device is ready (auto-launched or pre-existing) the script:
+
+1. builds the APK using `scripts/build_android_apk.sh`,
+2. installs it with `adb install -r -d` so debug smoke builds can replace newer local builds,
+3. force-stops the package by default for a clean launch,
+4. clears `logcat`,
+5. launches `com.ferrousapp.solitaire/android.app.NativeActivity`,
+6. waits for the app to settle,
+7. verifies the process is still running,
+8. captures a screenshot and `logcat`, and
+9. fails on fatal log patterns such as native crashes, JNI fatal errors, real ANRs,
+   and Rust panics.
+
+On exit the script kills any emulator it launched (`SHUTDOWN_AVD_ON_EXIT=1` by
+default). Set `SHUTDOWN_AVD_ON_EXIT=0` to keep the emulator open for inspection.
+
+Artifacts are written to `target/android-smoke/<timestamp>/` by default. A successful run includes:
+
+- `device.txt` — selected device and display metadata,
+- `df-data-before.txt` / `df-data-after.txt` — emulator/device storage snapshots,
+- `emulator.log` — stdout/stderr from the emulator process (AVD runs only),
+- `emulator.pid` — PID of the emulator process (AVD runs only),
+- `launch.png` — screenshot after the wait period,
+- `logcat.txt` — full captured log,
+- `log-summary.txt` — grep summary for warnings, errors, JNI, safe-area, and crash terms, and
+- `pid.txt` — running app process id.
+
+## Creating an AVD
+
+If no AVDs exist, create one before running the smoke test:
+
+```sh
+# Install a system image
+"$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" \
+  'system-images;android-34;google_apis;x86_64'
+
+# Create the AVD
+"$ANDROID_HOME/cmdline-tools/latest/bin/avdmanager" create avd \
+  -n Pixel_7_API_34 \
+  -k 'system-images;android-34;google_apis;x86_64' \
+  --device 'pixel_7'
+```
+
+Then run the smoke test — it will pick `Pixel_7_API_34` automatically:
+
+```sh
+scripts/android_smoke.sh
+```
+
+## Faster iteration
+
+If you already built the APK and only want to reinstall/relaunch:
+
+```sh
+BUILD_APK=0 scripts/android_smoke.sh
+```
+
+If the APK is already installed and you only want to relaunch/capture logs:
+
+```sh
+BUILD_APK=0 INSTALL_APK=0 scripts/android_smoke.sh
+```
+
+By default the script force-stops the package before launch so logcat and screenshots represent a clean app start. To test warm-launch behavior instead:
+
+```sh
+BUILD_APK=0 INSTALL_APK=0 FORCE_STOP=0 scripts/android_smoke.sh
+```
+
+This is also useful when an already-installed build is good enough for launch/log checks. On install failure, the script writes `adb-install.txt`, storage snapshots, and installed-package diagnostics to the output directory.
+
+If install fails with `INSTALL_FAILED_UPDATE_INCOMPATIBLE`, the smoke script uninstalls the package and retries once by default (`RESET_ON_SIGNATURE_MISMATCH=1`). This resets app data on the device/emulator. Disable it with:
+
+```sh
+RESET_ON_SIGNATURE_MISMATCH=0 scripts/android_smoke.sh
+```
+
+To write artifacts to a stable path:
+
+```sh
+OUT_DIR=target/android-smoke/latest scripts/android_smoke.sh
+```
+
+When reusing an output directory, previous files are removed by default so stale artifacts do not contaminate the latest result. To keep existing files:
+
+```sh
+CLEAN_OUT_DIR=0 OUT_DIR=target/android-smoke/latest scripts/android_smoke.sh
+```
+
+To target a specific device when more than one is attached:
+
+```sh
+ADB_SERIAL=emulator-5554 scripts/android_smoke.sh
+```
+
+To wait longer for safe-area inset polling or slow devices:
+
+```sh
+WAIT_SECS=8 scripts/android_smoke.sh
+```
+
+## AVD options
+
+To pick a specific AVD by name instead of auto-selecting the first one:
+
+```sh
+AVD_NAME=Pixel_7_API_34 scripts/android_smoke.sh
+```
+
+To run headless (no emulator window) — useful in CI or on a display-less machine:
+
+```sh
+AVD_HEADLESS=1 scripts/android_smoke.sh
+```
+
+To give a slow machine more time to boot the emulator (default is 120 s):
+
+```sh
+AVD_BOOT_TIMEOUT=180 scripts/android_smoke.sh
+```
+
+To keep the emulator running after the test (useful for manual inspection):
+
+```sh
+SHUTDOWN_AVD_ON_EXIT=0 scripts/android_smoke.sh
+```
+
+To pass extra flags to the emulator (e.g. disable snapshot for a completely
+cold boot, or change GPU mode):
+
+```sh
+AVD_EXTRA_ARGS="-gpu swiftshader_indirect" scripts/android_smoke.sh
+```
+
+To disable AVD auto-launch entirely and fail immediately if no device is
+connected:
+
+```sh
+LAUNCH_AVD=0 scripts/android_smoke.sh
+```
+
+For build-only validation without requiring a connected device, use the lower-level APK builder directly:
+
+```sh
+scripts/build_android_apk.sh
+```
+
+For smoke testing, `scripts/android_smoke.sh` defaults to the connected device's primary ABI when `BUILD_APK=1`, which keeps emulator APKs much smaller than the full multi-ABI default. You can still override it explicitly:
+
+```sh
+ABIS=x86_64 scripts/android_smoke.sh
+```
+
+For build-only validation, `scripts/build_android_apk.sh` still defaults to all configured ABIs unless you set `ABIS` yourself:
+
+```sh
+ABIS=x86_64 scripts/build_android_apk.sh
+```
+
+The APK builder signs debug builds with a persistent keystore at `target/android/debug.keystore` by default. This avoids signature churn across smoke-test runs.
+
+The APK builder also strips native debug symbols by default before packaging (`STRIP_NATIVE_LIBS=1`). This keeps debug APKs installable on emulators with limited `/data` storage. To preserve native debug symbols for low-level debugging:
+
+```sh
+STRIP_NATIVE_LIBS=0 ABIS=x86_64 scripts/build_android_apk.sh
+```
+
+## Device checklist
+
+The script is only a smoke test. Before shipping Android builds, also verify:
+
+- safe-area insets arrive and shift the HUD after a few seconds,
+- HUD does not overlap the top status bar,
+- modal Done buttons are above the gesture/navigation bar,
+- stock tap works,
+- drag-and-drop works on tableau, waste, and foundation piles,
+- Settings/Help/Profile modals open and close,
+- login tokens persist after app restart, and
+- `target/android-smoke/.../logcat.txt` contains no fatal JNI/native crash output.
+
+## Notes
+
+- `adb shell input tap X Y` uses physical pixels, not Bevy logical pixels.
+- The project’s common test device mapping is physical `1080×2400`, Bevy logical
+  `900×2000`, scale factor `1.20`; multiply logical coordinates by `1.20` for
+  scripted `adb shell input` commands on that device.
+- Keep generated screenshots/logs under `target/android-smoke/` so they stay out
+  of source control.
diff --git a/scripts/android_smoke.sh b/scripts/android_smoke.sh
new file mode 100755
index 0000000..ea87ae2
--- /dev/null
+++ b/scripts/android_smoke.sh
@@ -0,0 +1,362 @@
+#!/usr/bin/env bash
+# Android smoke test for Ferrous Solitaire.
+#
+# Builds (optional), installs, launches, captures logcat + screenshot, and
+# fails on fatal Android log patterns. Designed as a lightweight device/emulator
+# sanity check rather than a full UI automation suite.
+#
+# Required:
+#   adb on PATH
+#   Android SDK/NDK env required by scripts/build_android_apk.sh when BUILD_APK=1
+#
+# Optional environment:
+#   BUILD_APK=1|0          Build APK before install (default: 1)
+#   INSTALL_APK=1|0        Install APK before launch (default: 1)
+#   RESET_ON_SIGNATURE_MISMATCH=1|0
+#                           Uninstall/retry if debug signatures differ (default: 1)
+#   LAUNCH_APP=1|0         Launch app before checks (default: 1)
+#   FORCE_STOP=1|0         Force-stop package before launch for clean logs (default: 1)
+#   CAPTURE_SCREENSHOT=1|0 Capture screenshot (default: 1)
+#   ADB_SERIAL=...         Device serial to use when multiple devices are connected
+#   APK_PATH=...           APK to install (default: target/debug/apk/ferrous-solitaire.apk)
+#   PACKAGE=...            Android package (default: com.ferrousapp.solitaire)
+#   ACTIVITY=...           Activity class (default: android.app.NativeActivity)
+#   OUT_DIR=...            Artifact directory (default: target/android-smoke/<timestamp>)
+#   CLEAN_OUT_DIR=1|0      Remove prior artifacts from OUT_DIR first (default: 1)
+#   WAIT_SECS=...          Seconds to wait after launch (default: 5)
+#   ABIS=...               Passed to build script. If unset and BUILD_APK=1,
+#                           defaults to the connected device's primary ABI.
+#
+# AVD auto-launch (used when no device/emulator is already connected):
+#   LAUNCH_AVD=1|0         Auto-launch an AVD when no device is ready (default: 1)
+#   AVD_NAME=...           AVD name to launch (default: first from `emulator -list-avds`)
+#   AVD_BOOT_TIMEOUT=...   Seconds to wait for the emulator to finish booting (default: 120)
+#   AVD_HEADLESS=1|0       Run with -no-window -no-audio for CI/no-display environments (default: 0)
+#   AVD_EXTRA_ARGS=...     Extra arguments appended verbatim to the emulator command line
+#   SHUTDOWN_AVD_ON_EXIT=1|0
+#                           Kill the AVD this script launched on exit (default: 1).
+#                           Set to 0 to leave the emulator running after the test.
+#
+# Examples:
+#   scripts/android_smoke.sh
+#   BUILD_APK=0 scripts/android_smoke.sh
+#   LAUNCH_AVD=0 scripts/android_smoke.sh            # error out if no device, never auto-launch
+#   AVD_NAME=Pixel_7_API_34 scripts/android_smoke.sh
+#   AVD_HEADLESS=1 scripts/android_smoke.sh          # CI / no-display
+#   SHUTDOWN_AVD_ON_EXIT=0 scripts/android_smoke.sh  # keep emulator open after test
+#   OUT_DIR=target/android-smoke/latest WAIT_SECS=8 scripts/android_smoke.sh
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+BUILD_APK="${BUILD_APK:-1}"
+INSTALL_APK="${INSTALL_APK:-1}"
+RESET_ON_SIGNATURE_MISMATCH="${RESET_ON_SIGNATURE_MISMATCH:-1}"
+LAUNCH_APP="${LAUNCH_APP:-1}"
+FORCE_STOP="${FORCE_STOP:-1}"
+CAPTURE_SCREENSHOT="${CAPTURE_SCREENSHOT:-1}"
+APK_PATH="${APK_PATH:-target/debug/apk/ferrous-solitaire.apk}"
+PACKAGE="${PACKAGE:-com.ferrousapp.solitaire}"
+ACTIVITY="${ACTIVITY:-android.app.NativeActivity}"
+WAIT_SECS="${WAIT_SECS:-5}"
+OUT_DIR="${OUT_DIR:-target/android-smoke/$(date +%Y%m%d-%H%M%S)}"
+CLEAN_OUT_DIR="${CLEAN_OUT_DIR:-1}"
+REMOTE_SCREENSHOT="/sdcard/ferrous-solitaire-smoke.png"
+
+LAUNCH_AVD="${LAUNCH_AVD:-1}"
+AVD_NAME="${AVD_NAME:-}"
+AVD_BOOT_TIMEOUT="${AVD_BOOT_TIMEOUT:-120}"
+AVD_HEADLESS="${AVD_HEADLESS:-0}"
+AVD_EXTRA_ARGS="${AVD_EXTRA_ARGS:-}"
+SHUTDOWN_AVD_ON_EXIT="${SHUTDOWN_AVD_ON_EXIT:-1}"
+
+ADB=(adb)
+if [ -n "${ADB_SERIAL:-}" ]; then
+  ADB+=( -s "$ADB_SERIAL" )
+fi
+
+# PID of any emulator we start so the EXIT trap can clean it up.
+_LAUNCHED_EMULATOR_PID=""
+
+_cleanup_emulator() {
+  if [ -n "$_LAUNCHED_EMULATOR_PID" ] && [ "$SHUTDOWN_AVD_ON_EXIT" = "1" ]; then
+    echo ">>> shutdown emulator (PID $_LAUNCHED_EMULATOR_PID)"
+    kill "$_LAUNCHED_EMULATOR_PID" 2>/dev/null || true
+  fi
+}
+trap _cleanup_emulator EXIT
+
+require_cmd() {
+  command -v "$1" >/dev/null 2>&1 || {
+    echo "missing required command: $1" >&2
+    exit 1
+  }
+}
+
+mkdir -p "$OUT_DIR"
+if [ "$CLEAN_OUT_DIR" = "1" ]; then
+  find "$OUT_DIR" -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+fi
+require_cmd adb
+
+# ---------------------------------------------------------------------------
+# Device / emulator availability
+# ---------------------------------------------------------------------------
+DEVICE_STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+if [ "$DEVICE_STATE" != "device" ]; then
+  if [ "$LAUNCH_AVD" != "1" ]; then
+    adb devices > "$OUT_DIR/adb-devices.txt" 2>&1 || true
+    if [ -n "${ADB_SERIAL:-}" ]; then
+      echo "Android device '$ADB_SERIAL' is not connected/ready (state: ${DEVICE_STATE:-unknown})." >&2
+    else
+      echo "No Android device/emulator is connected and ready." >&2
+    fi
+    echo "Run 'adb devices' or start an emulator, then retry." >&2
+    echo "Device list saved to $OUT_DIR/adb-devices.txt" >&2
+    exit 1
+  fi
+
+  # --- locate emulator binary -----------------------------------------------
+  # Priority: ANDROID_HOME env → PATH → common SDK install locations.
+  _find_sdk_root() {
+    for candidate in \
+        "$HOME/Android/Sdk" \
+        "$HOME/Library/Android/sdk" \
+        "/opt/android-sdk" \
+        "/usr/lib/android-sdk"; do
+      [ -d "$candidate" ] && echo "$candidate" && return
+    done
+  }
+
+  EMULATOR_BIN=""
+  if [ -n "${ANDROID_HOME:-}" ] && [ -x "$ANDROID_HOME/emulator/emulator" ]; then
+    EMULATOR_BIN="$ANDROID_HOME/emulator/emulator"
+  elif command -v emulator >/dev/null 2>&1; then
+    EMULATOR_BIN="$(command -v emulator)"
+  else
+    _SDK_ROOT="$(_find_sdk_root)"
+    if [ -n "$_SDK_ROOT" ] && [ -x "$_SDK_ROOT/emulator/emulator" ]; then
+      EMULATOR_BIN="$_SDK_ROOT/emulator/emulator"
+    fi
+  fi
+
+  if [ -z "$EMULATOR_BIN" ]; then
+    echo "No Android device found and 'emulator' binary is not available." >&2
+    echo "  • Install the Android SDK emulator component, or" >&2
+    echo "  • Set ANDROID_HOME to your SDK root, or" >&2
+    echo "  • Start a device/emulator manually then retry with LAUNCH_AVD=0." >&2
+    exit 1
+  fi
+  echo ">>> emulator binary: $EMULATOR_BIN"
+
+  # --- select AVD -----------------------------------------------------------
+  if [ -z "$AVD_NAME" ]; then
+    AVD_NAME="$("$EMULATOR_BIN" -list-avds 2>/dev/null | head -n 1 | tr -d '\r')"
+    if [ -z "$AVD_NAME" ]; then
+      echo "No AVDs found. Create one first, for example:" >&2
+      echo "  sdkmanager 'system-images;android-34;google_apis;x86_64'" >&2
+      echo "  avdmanager create avd -n Pixel_7_API_34 \\" >&2
+      echo "    -k 'system-images;android-34;google_apis;x86_64' --device 'pixel_7'" >&2
+      exit 1
+    fi
+    echo ">>> auto-selected AVD: $AVD_NAME"
+  fi
+
+  # --- launch emulator -------------------------------------------------------
+  EMULATOR_ARGS=( -avd "$AVD_NAME" -no-snapshot-load )
+  [ "$AVD_HEADLESS" = "1" ] && EMULATOR_ARGS+=( -no-window -no-audio )
+  # Split AVD_EXTRA_ARGS on whitespace only (disable glob expansion).
+  set -f
+  # shellcheck disable=SC2206
+  [ -n "$AVD_EXTRA_ARGS" ] && EMULATOR_ARGS+=( $AVD_EXTRA_ARGS )
+  set +f
+
+  echo ">>> launch emulator: $AVD_NAME"
+  "$EMULATOR_BIN" "${EMULATOR_ARGS[@]}" > "$OUT_DIR/emulator.log" 2>&1 &
+  _LAUNCHED_EMULATOR_PID=$!
+  echo "$_LAUNCHED_EMULATOR_PID" > "$OUT_DIR/emulator.pid"
+  echo "    emulator PID: $_LAUNCHED_EMULATOR_PID"
+  echo "    emulator log: $OUT_DIR/emulator.log"
+
+  # --- wait for adb transport -----------------------------------------------
+  # Poll adb get-state (≠ wait-for-device which blocks indefinitely) so we can
+  # honour AVD_BOOT_TIMEOUT for the whole boot sequence.
+  echo ">>> waiting for device to appear in adb (timeout: ${AVD_BOOT_TIMEOUT}s)"
+  _ELAPSED=0
+  while true; do
+    _STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+    if [ "$_STATE" = "device" ] || [ "$_STATE" = "offline" ]; then
+      break
+    fi
+    if [ "$_ELAPSED" -ge "$AVD_BOOT_TIMEOUT" ]; then
+      echo "Device did not appear in adb within ${AVD_BOOT_TIMEOUT}s" >&2
+      echo "emulator log:" >&2
+      tail -20 "$OUT_DIR/emulator.log" >&2 || true
+      exit 1
+    fi
+    sleep 3
+    _ELAPSED=$(( _ELAPSED + 3 ))
+    echo "    ... ${_ELAPSED}s / ${AVD_BOOT_TIMEOUT}s"
+  done
+
+  # Capture emulator serial (emulator-5554 etc.) so all subsequent adb calls
+  # target the right device when ADB_SERIAL was not set by the caller.
+  if [ -z "${ADB_SERIAL:-}" ]; then
+    _EMU_SERIAL="$(adb devices 2>/dev/null | awk '/^emulator-/{print $1; exit}' | tr -d '\r')"
+    if [ -n "$_EMU_SERIAL" ]; then
+      ADB_SERIAL="$_EMU_SERIAL"
+      ADB=(adb -s "$ADB_SERIAL")
+      echo ">>> detected emulator serial: $ADB_SERIAL"
+    fi
+  fi
+
+  # --- wait for full Android boot -------------------------------------------
+  # adb get-state returning "device" means the transport is up, but the
+  # Android framework may still be initialising. Poll sys.boot_completed.
+  echo ">>> waiting for boot_completed (timeout: ${AVD_BOOT_TIMEOUT}s)"
+  _BOOT_ELAPSED=0
+  _BOOT_INTERVAL=5
+  while true; do
+    _BOOT="$("${ADB[@]}" shell getprop sys.boot_completed 2>/dev/null | tr -d '\r')"
+    if [ "$_BOOT" = "1" ]; then
+      echo ">>> emulator boot complete"
+      break
+    fi
+    if [ "$_BOOT_ELAPSED" -ge "$AVD_BOOT_TIMEOUT" ]; then
+      echo "Emulator did not finish booting within ${AVD_BOOT_TIMEOUT}s" >&2
+      echo "emulator log:" >&2
+      tail -20 "$OUT_DIR/emulator.log" >&2 || true
+      exit 1
+    fi
+    sleep "$_BOOT_INTERVAL"
+    _BOOT_ELAPSED=$(( _BOOT_ELAPSED + _BOOT_INTERVAL ))
+    echo "    ... ${_BOOT_ELAPSED}s / ${AVD_BOOT_TIMEOUT}s (boot_completed='${_BOOT}')"
+  done
+
+  # Dismiss the lock screen so later screencap shows the app, not the keyguard.
+  "${ADB[@]}" shell input keyevent 82 2>/dev/null || true
+
+  # Final sanity check — device must be fully ready before we proceed.
+  DEVICE_STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+  if [ "$DEVICE_STATE" != "device" ]; then
+    echo "Emulator is running but adb state is '${DEVICE_STATE:-unknown}'." >&2
+    exit 1
+  fi
+fi
+
+# ---------------------------------------------------------------------------
+# Device metadata
+# ---------------------------------------------------------------------------
+{
+  echo "adb_serial=${ADB_SERIAL:-default}"
+  echo "package=$PACKAGE"
+  echo "activity=$ACTIVITY"
+  echo "device_state=$DEVICE_STATE"
+  "${ADB[@]}" shell getprop ro.product.model 2>/dev/null | tr -d '\r' | sed 's/^/product_model=/'
+  "${ADB[@]}" shell getprop ro.build.version.release 2>/dev/null | tr -d '\r' | sed 's/^/android_release=/'
+  "${ADB[@]}" shell getprop ro.build.version.sdk 2>/dev/null | tr -d '\r' | sed 's/^/android_sdk=/'
+  "${ADB[@]}" shell wm size 2>/dev/null | tr -d '\r' | sed 's/^/wm_size=/'
+  "${ADB[@]}" shell wm density 2>/dev/null | tr -d '\r' | sed 's/^/wm_density=/'
+} > "$OUT_DIR/device.txt"
+"${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-before.txt" 2>&1 || true
+
+if [ "$BUILD_APK" = "1" ]; then
+  if [ -z "${ABIS:-}" ]; then
+    DEVICE_ABI="$("${ADB[@]}" shell getprop ro.product.cpu.abi 2>/dev/null | tr -d '\r')"
+    case "$DEVICE_ABI" in
+      x86_64|arm64-v8a|armeabi-v7a)
+        export ABIS="$DEVICE_ABI"
+        ;;
+      armeabi*)
+        export ABIS="armeabi-v7a"
+        ;;
+      *)
+        echo "Could not map device ABI '$DEVICE_ABI'; using build script default ABIS." >&2
+        ;;
+    esac
+  fi
+  echo ">>> build Android APK${ABIS:+ (ABIS=$ABIS)}"
+  scripts/build_android_apk.sh
+fi
+
+if [ "$INSTALL_APK" = "1" ]; then
+  [ -f "$APK_PATH" ] || {
+    echo "APK not found: $APK_PATH" >&2
+    echo "Set APK_PATH or run with BUILD_APK=1." >&2
+    exit 1
+  }
+  ls -lh "$APK_PATH" > "$OUT_DIR/apk.txt"
+  echo ">>> install $APK_PATH"
+  if ! "${ADB[@]}" install -r -d "$APK_PATH" > "$OUT_DIR/adb-install.txt" 2>&1; then
+    if [ "$RESET_ON_SIGNATURE_MISMATCH" = "1" ] && grep -q "INSTALL_FAILED_UPDATE_INCOMPATIBLE" "$OUT_DIR/adb-install.txt"; then
+      echo ">>> signature mismatch; uninstalling $PACKAGE and retrying install"
+      "${ADB[@]}" uninstall "$PACKAGE" > "$OUT_DIR/adb-uninstall-before-retry.txt" 2>&1 || true
+      if "${ADB[@]}" install -r -d "$APK_PATH" > "$OUT_DIR/adb-install-retry.txt" 2>&1; then
+        cat "$OUT_DIR/adb-install-retry.txt" >> "$OUT_DIR/adb-install.txt"
+      else
+        cat "$OUT_DIR/adb-install.txt" >&2
+        cat "$OUT_DIR/adb-install-retry.txt" >&2
+        "${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after-install-failure.txt" 2>&1 || true
+        "${ADB[@]}" shell pm list packages | grep -F "$PACKAGE" > "$OUT_DIR/installed-package.txt" 2>&1 || true
+        echo "APK install retry failed. Diagnostics saved in $OUT_DIR" >&2
+        exit 1
+      fi
+    else
+      cat "$OUT_DIR/adb-install.txt" >&2
+      "${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after-install-failure.txt" 2>&1 || true
+      "${ADB[@]}" shell pm list packages | grep -F "$PACKAGE" > "$OUT_DIR/installed-package.txt" 2>&1 || true
+      echo "APK install failed. Diagnostics saved in $OUT_DIR" >&2
+      echo "If the package is already installed and you only need launch/log checks, retry with INSTALL_APK=0." >&2
+      exit 1
+    fi
+  fi
+fi
+
+if [ "$FORCE_STOP" = "1" ]; then
+  echo ">>> force-stop $PACKAGE"
+  "${ADB[@]}" shell am force-stop "$PACKAGE" || true
+fi
+
+echo ">>> clear logcat"
+"${ADB[@]}" logcat -c
+
+if [ "$LAUNCH_APP" = "1" ]; then
+  echo ">>> launch $PACKAGE/$ACTIVITY"
+  "${ADB[@]}" shell am start -n "$PACKAGE/$ACTIVITY" > "$OUT_DIR/am-start.txt"
+fi
+
+echo ">>> wait ${WAIT_SECS}s"
+sleep "$WAIT_SECS"
+
+PID="$("${ADB[@]}" shell pidof "$PACKAGE" | tr -d '\r' || true)"
+if [ -z "$PID" ]; then
+  "${ADB[@]}" logcat -d > "$OUT_DIR/logcat.txt" || true
+  echo "app process is not running after launch: $PACKAGE" >&2
+  echo "logcat saved to $OUT_DIR/logcat.txt" >&2
+  exit 1
+fi
+echo "$PID" > "$OUT_DIR/pid.txt"
+
+if [ "$CAPTURE_SCREENSHOT" = "1" ]; then
+  echo ">>> capture screenshot"
+  "${ADB[@]}" shell screencap -p "$REMOTE_SCREENSHOT"
+  "${ADB[@]}" pull "$REMOTE_SCREENSHOT" "$OUT_DIR/launch.png" >/dev/null
+  "${ADB[@]}" shell rm -f "$REMOTE_SCREENSHOT" >/dev/null 2>&1 || true
+fi
+
+echo ">>> capture logcat"
+"${ADB[@]}" logcat -d > "$OUT_DIR/logcat.txt"
+grep -iE "panic|fatal|jni|native crash|\bANR\b|exception|error|warn|keystore|safe_area" "$OUT_DIR/logcat.txt" > "$OUT_DIR/log-summary.txt" || true
+"${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after.txt" 2>&1 || true
+
+# Fatal patterns only. Avoid matching generic "error" because Android logs are
+# noisy and many non-fatal framework lines contain that word.
+if grep -iE "fatal exception|jni detected error|native crash|signal [0-9]+|ANR in|Application Not Responding|Input dispatching timed out|thread exiting with uncaught exception|panicked at" "$OUT_DIR/logcat.txt"; then
+  echo "Android smoke test found fatal log output" >&2
+  echo "Artifacts saved in $OUT_DIR" >&2
+  exit 1
+fi
+
+echo ">>> Android smoke test passed"
+echo "Artifacts saved in $OUT_DIR"
diff --git a/scripts/build_android_apk.sh b/scripts/build_android_apk.sh
index 99df4ab..39c5119 100755
--- a/scripts/build_android_apk.sh
+++ b/scripts/build_android_apk.sh
@@ -6,11 +6,15 @@
 # ndk-build crate that we couldn't isolate; running each Android toolchain
 # step explicitly gives us a debuggable pipeline.
 #
-# Required environment:
-#   ANDROID_HOME            Path to Android SDK root
-#   ANDROID_NDK_HOME        Path to the specific NDK version
-#   BUILD_TOOLS_VERSION     e.g. "34.0.0"
-#   PLATFORM                e.g. "android-34"
+# Environment:
+#   ANDROID_HOME            Path to Android SDK root. If unset, common SDK
+#                           locations such as ~/Android/Sdk are tried.
+#   ANDROID_NDK_HOME        Path to the specific NDK version. If unset, the
+#                           newest $ANDROID_HOME/ndk/* directory is used.
+#   BUILD_TOOLS_VERSION     e.g. "34.0.0". If unset, newest installed build-tools
+#                           version is used.
+#   PLATFORM                e.g. "android-34". If unset, newest installed
+#                           $ANDROID_HOME/platforms/android-* platform is used.
 #
 # Optional environment:
 #   PROFILE                 "debug" (default) | "release"
@@ -19,7 +23,8 @@
 #                           fit the runner's disk budget — a full three-ABI
 #                           debug build can exceed 25 GB of target/ output.
 #   APK_OUT                 Output APK path (default: target/$PROFILE/apk/ferrous-solitaire.apk)
-#   KEYSTORE                Path to keystore for signing (default: generates a debug keystore)
+#   STRIP_NATIVE_LIBS       1 to strip .so files before packaging (default: 1)
+#   KEYSTORE                Path to keystore for signing (default: target/android/debug.keystore)
 #   KEYSTORE_PASS           Keystore password (default: "android" for the generated debug keystore)
 #   KEY_ALIAS               Key alias (default: "androiddebugkey")
 #   KEY_PASS                Key password (default: same as KEYSTORE_PASS)
@@ -28,18 +33,63 @@
 #   $APK_OUT                Signed, zipaligned APK
 set -euo pipefail
 
-: "${ANDROID_HOME:?ANDROID_HOME must be set}"
-: "${ANDROID_NDK_HOME:?ANDROID_NDK_HOME must be set}"
-: "${BUILD_TOOLS_VERSION:?BUILD_TOOLS_VERSION must be set}"
-: "${PLATFORM:?PLATFORM must be set (e.g. android-34)}"
+infer_latest_dir_name() {
+  local pattern="$1"
+  local latest=""
+  shopt -s nullglob
+  local dirs=( $pattern )
+  shopt -u nullglob
+  if [ ${#dirs[@]} -gt 0 ]; then
+    latest="$(printf '%s\n' "${dirs[@]}" | sort -V | tail -n 1)"
+    basename "$latest"
+  fi
+}
+
+if [ -z "${ANDROID_HOME:-}" ]; then
+  for candidate in "$HOME/Android/Sdk" "$HOME/Library/Android/sdk" "/opt/android-sdk" "/usr/lib/android-sdk"; do
+    if [ -d "$candidate" ]; then
+      ANDROID_HOME="$candidate"
+      export ANDROID_HOME
+      break
+    fi
+  done
+fi
+: "${ANDROID_HOME:?ANDROID_HOME must be set or discoverable under a common SDK path}"
+
+if [ -z "${ANDROID_NDK_HOME:-}" ]; then
+  NDK_VERSION="$(infer_latest_dir_name "$ANDROID_HOME/ndk/*")"
+  if [ -n "$NDK_VERSION" ]; then
+    ANDROID_NDK_HOME="$ANDROID_HOME/ndk/$NDK_VERSION"
+    export ANDROID_NDK_HOME
+  fi
+fi
+: "${ANDROID_NDK_HOME:?ANDROID_NDK_HOME must be set or discoverable under ANDROID_HOME/ndk}"
+
+if [ -z "${BUILD_TOOLS_VERSION:-}" ]; then
+  BUILD_TOOLS_VERSION="$(infer_latest_dir_name "$ANDROID_HOME/build-tools/*")"
+  export BUILD_TOOLS_VERSION
+fi
+: "${BUILD_TOOLS_VERSION:?BUILD_TOOLS_VERSION must be set or discoverable under ANDROID_HOME/build-tools}"
+
+if [ -z "${PLATFORM:-}" ]; then
+  PLATFORM="$(infer_latest_dir_name "$ANDROID_HOME/platforms/android-*")"
+  export PLATFORM
+fi
+: "${PLATFORM:?PLATFORM must be set or discoverable under ANDROID_HOME/platforms}"
 
 PROFILE="${PROFILE:-debug}"
 ABIS="${ABIS:-arm64-v8a armeabi-v7a x86_64}"
 APK_OUT="${APK_OUT:-target/${PROFILE}/apk/ferrous-solitaire.apk}"
+STRIP_NATIVE_LIBS="${STRIP_NATIVE_LIBS:-1}"
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "$REPO_ROOT"
 
+echo ">>> Android SDK: $ANDROID_HOME"
+echo ">>> Android NDK: $ANDROID_NDK_HOME"
+echo ">>> Build tools: $BUILD_TOOLS_VERSION"
+echo ">>> Platform: $PLATFORM"
+
 BT="$ANDROID_HOME/build-tools/$BUILD_TOOLS_VERSION"
 PLATFORM_JAR="$ANDROID_HOME/platforms/$PLATFORM/android.jar"
 MANIFEST="solitaire_app/android/AndroidManifest.xml"
@@ -69,6 +119,24 @@ fi
 echo ">>> cargo ndk ${CARGO_NDK_ARGS[*]}"
 cargo ndk "${CARGO_NDK_ARGS[@]}"
 
+if [ "$STRIP_NATIVE_LIBS" = "1" ]; then
+  LLVM_STRIP=""
+  shopt -s nullglob
+  STRIP_CANDIDATES=( "$ANDROID_NDK_HOME"/toolchains/llvm/prebuilt/*/bin/llvm-strip )
+  shopt -u nullglob
+  if [ ${#STRIP_CANDIDATES[@]} -gt 0 ]; then
+    LLVM_STRIP="${STRIP_CANDIDATES[0]}"
+  fi
+  if [ -z "$LLVM_STRIP" ]; then
+    echo "llvm-strip not found under ANDROID_NDK_HOME; native libraries will remain unstripped" >&2
+  else
+    echo ">>> strip native libraries with $LLVM_STRIP"
+    find "$STAGING/lib" -name '*.so' -print0 | while IFS= read -r -d '' so; do
+      "$LLVM_STRIP" --strip-debug "$so"
+    done
+  fi
+fi
+
 # --- 2. compile + link resources and manifest ------------------------------
 if [ -d "$RES_DIR" ]; then
   echo ">>> aapt2 compile resources"
@@ -120,11 +188,15 @@ rm -f "$STAGING/app-unsigned.apk"
 
 # --- 5. sign ---------------------------------------------------------------
 if [ -z "${KEYSTORE:-}" ]; then
-  # Generate a deterministic debug keystore on the fly.
-  KEYSTORE="$STAGING/debug.keystore"
-  KEYSTORE_PASS="${KEYSTORE_PASS:-android}"
-  KEY_ALIAS="${KEY_ALIAS:-androiddebugkey}"
-  KEY_PASS="${KEY_PASS:-$KEYSTORE_PASS}"
+  KEYSTORE="target/android/debug.keystore"
+fi
+
+KEYSTORE_PASS="${KEYSTORE_PASS:-android}"
+KEY_ALIAS="${KEY_ALIAS:-androiddebugkey}"
+KEY_PASS="${KEY_PASS:-$KEYSTORE_PASS}"
+
+if [ ! -f "$KEYSTORE" ]; then
+  mkdir -p "$(dirname "$KEYSTORE")"
   echo ">>> generating debug keystore at $KEYSTORE"
   keytool -genkeypair -v \
     -keystore "$KEYSTORE" \