perf(r8): keep exception names without keeping every exception

apps/flipcash/app/proguard-rules.pro

@@ -1,7 +1,9 @@
 # Preserve source file names and line numbers for stack traces (call site tracking, Bugsnag)
 -keepattributes SourceFile,LineNumberTable
 
-# Keep AppRoute class names for analytics screen tracking
+# Keep AppRoute class names. `annotatedEntry` derives each screen's root test tag
+# from the route's simple name (NavMetadata.screenRootTag), so obfuscating these
+# renames every screen-root resource-id the UI tests address.
 -keepnames class com.flipcash.app.core.AppRoute
 -keepnames class com.flipcash.app.core.AppRoute$**
 
@@ -15,7 +17,11 @@
 -keep class * extends io.grpc.stub.AbstractStub { *; }
 -keep class * implements io.grpc.BindableService { *; }
 
-# Keep our scan classes that interact with native
+# Keep our scan classes that interact with native. The scanner's JNI constructs
+# these from C++ by name (FindClass("com/kik/scan/UsernameKikCode"), GetMethodID
+# for <init>) and reads their backing fields directly (GetFieldID for "_username",
+# "nativePtr"), none of which AGP's default native-methods rule covers. Five
+# classes, so the wildcard costs little.
 -keep class com.kik.scan.** { *; }
 
 -assumenosideeffects class android.util.Log {
@@ -26,4 +32,10 @@
     public static int e(...);
 }
 
--keep public class * extends java.lang.Throwable
+# Error telemetry reads exception names at runtime — Coinbase onramp traces send
+# `it::class.simpleName` as `errorType`, and Events.kt does the same for analytics.
+# Those are plain strings by the time they leave the device, so the Bugsnag mapping
+# upload cannot repair them; the names have to survive obfuscation. Nothing reads
+# the members, and an exception nothing throws need not survive, so this is
+# -keepnames rather than a full keep.
+-keepnames public class * extends java.lang.Throwable