APK→JAR conversion emits invalid bytecode for Kotlin 2.x extensions (InstantiationError: kotlin.jvm.internal.Lambda)

Summary

Extensions built by keiyoushi after their Kotlin 2.x / Mihon 0.20 migration fail to install on Suwayomi with java.lang.InstantiationError: kotlin.jvm.internal.Lambda. Root cause: the APK?JAR conversion emits a literal new kotlin/jvm/internal/Lambda instruction where the original Android build constructs the concrete subclass. On current Suwayomi runtimes kotlin.jvm.internal.Lambda is abstract (generic Lambda<R>), so the invalid new throws InstantiationError.

Environment

• Suwayomi-Server v2.3.2243 (stable) and v2.3.2333 (preview) � both affected
• Java 21.0.8 (bundled JRE), Windows x64
• Extension: eu.kanade.tachiyomi.extension.en.flamecomics v1.4.50 (keiyoushi)

Reproduction

1. Install any post-migration keiyoushi extension (e.g. flamecomics v1.4.50)
2. Install fails with:

Caused by: java.lang.InstantiationError: kotlin.jvm.internal.Lambda
    at y.<clinit>(Unknown Source)
    at eu.kanade.tachiyomi.extension.en.flamecomics.ExtensionGenerated.<init>(Unknown Source)

1. Same APK works fine on Mihon/J2K (Android ART loads the extension with its own bundled stdlib)

Evidence

Converted jar inspection (extensions/tachiyomi-en.flamecomics-v1.4.50.jar):

• 71 entries, zero kotlin/ classes (conversion drops the bundled stdlib)
• javap y:

public final class y extends kotlin.jvm.internal.Lambda implements kotlin.jvm.functions.Function0
  public static final y a;
  static {};

• Runtime failure at y.<clinit>: the emitted new kotlin.jvm.internal.Lambda resolves against the server's abstract Lambda<R> ? InstantiationError
• Verified with multiple Kotlin stdlib versions injected via a child-first classloader (1.9.0, 2.2.10, 2.2.21, 2.3.10, 2.3.20, 2.4.0) � all fail identically, confirming the emitted instruction itself is invalid for current runtimes
• Windows Event Log shows the JVM dying natively in unrelated KCEF cases, but this specific failure is a clean Java-level InstantiationError

Impact

Every keiyoushi extension built after the Kotlin 2.x migration fails to install on any published Suwayomi release (stable and preview). This blocks the whole Mihon-extension ecosystem on Suwayomi going forward.

Expected

The APK?JAR conversion (and/or its bytecode patching step) should emit new y (the concrete generated lambda subclass) � or otherwise handle Kotlin 2.x lambda shapes � so extensions load against the server-provided stdlib.

Happy to provide the converted jar, the original APK, or test candidate fixes against our instance.