fix: use type-hierarchy proguard rules for protobuf/gRPC

Signed-off-by: Brandon McAnsh <git@bmcreations.dev>

Author: bmc08gt

apps/flipcash/app/proguard-rules.pro

@@ -16,16 +16,21 @@
 # Keep screen names
 -keepnames class * implements cafe.adriel.voyager.core.screen.Screen
 
-# Flipcash protos
--keep class com.codeinc.flipcash.gen.** {*;}
+# Protobuf — keep all generated message classes and their builders.
+# Using type-hierarchy rules so new packages / updated gRPC stubs are
+# caught automatically instead of listing every gen package.
+-keep class com.google.protobuf.** { *; }
+-keep class * extends com.google.protobuf.GeneratedMessageLite { *; }
+-keep class * extends com.google.protobuf.GeneratedMessageLite$Builder { *; }
+
+# gRPC — keep generated service stubs (abstract + concrete)
+-keep class * extends io.grpc.stub.AbstractStub { *; }
+-keep class * implements io.grpc.BindableService { *; }
+
 # Flipcash services
--keep class com.flipcash.services.** {*;}
-# Opencode protos
--keep class com.codeinc.opencode.gen.** {*;}
+-keep class com.flipcash.services.** { *; }
 # Opencode services
--keep class com.getcode.opencode.** {*;}
-
--keep class com.google.protobuf.** { *; }
+-keep class com.getcode.opencode.** { *; }
 
 # Keep our scan classes that interact with native
 -keep class com.kik.scan.** { *; }