fix(desktop): disable proguard return-type specialization breaking compose text

Author: maxrave-dev

composeApp/proguard-desktop-rules.pro

@@ -1,3 +1,11 @@
+# ProGuard's return-type specialization narrows ActualParagraph()'s declared return type
+# from the Paragraph interface down to its only impl (SkiaParagraph). The bytecode still
+# pushes a Paragraph-typed value, so JVM 21's verifier rejects it at runtime with
+# "VerifyError: Bad return type" the moment any Text() renders (androidx.compose.ui.text).
+# Disable only method type-specialization; shrinking, obfuscation, class-merging,
+# inlining and every other optimization stay on.
+-optimizations !method/specialization/*
+
 -keepclasseswithmembers class * {
     native <methods>;
 }