Enable R8 for release; keep the JNI bridge and app packages so native callbacks survive

android/app/build.gradle

@@ -158,8 +158,8 @@ android {
             if (hasRepoDebugKeystore) {
                 signingConfig signingConfigs.debug
             }
-            minifyEnabled false
-            shrinkResources false
+            minifyEnabled true
+            shrinkResources true
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }

android/app/proguard-rules.pro

@@ -1,3 +1,27 @@
 -dontwarn org.libsdl.app.**
 -keep class org.libsdl.app.** { *; }
+
+# The application ID is com.nanodata.armsx but the SOURCES live in com.armsx2 — this rule
+# only ever matched the former, i.e. nothing. Kept for safety, but the real packages are below.
 -keepclassmembers class com.nanodata.armsx.** { *; }
+
+# ---------------------------------------------------------------------------------------
+# JNI. R8 cannot see a method that only C++ reaches through GetMethodID(), so anything
+# native calls BACK into looks dead and gets renamed or stripped. That fails at runtime with
+# no crash and no log — the feature is simply silently gone (sound effects, rumble, RA
+# toasts). frontend/android_jni.cpp resolves kr/co/iefriends/pcsx2/NativeApp and calls
+# playSound on it, so this whole bridge must survive verbatim, names included.
+-keep class kr.co.iefriends.pcsx2.** { *; }
+-keepclassmembers class kr.co.iefriends.pcsx2.** { *; }
+
+# Java->native declarations. The default optimize config carries this too; being explicit so
+# it cannot be lost if the default file is ever swapped.
+-keepclasseswithmembernames,includedescriptorclasses class * {
+    native <methods>;
+}
+
+# The app's actual sources. Broad on purpose: the JNI surface, Compose entry points and the
+# settings serialisation are all name-sensitive, and a wrong-but-quiet release build costs far
+# more than the few MB this gives back. Narrow it only with a device pass behind it.
+-keep class com.armsx2.** { *; }
+-keepclassmembers class com.armsx2.** { *; }