v0.8.19

• Updated the default llama.cpp native runtime pin to
  leehack/llamadart-native@b10333, regenerated matching Dart FFI bindings,
  refreshed the llamadart_llama_cpp_flutter Apple SwiftPM checksum, and aligned
  current README/website native override docs.

• Updated WebGPU bridge assets to v0.1.27 (llama.cpp b10333), keeping the
  native and Web GGUF runtimes on the same upstream revision.

• Fixed corrupt Qwen3.5 output on Android Vulkan by preserving the KQV
  offload required for correct hybrid model inference while retaining the
  remaining conservative Android context settings.