Language bindings, KDE thumbnails, yapf compare, in-memory encoding

- yapf_encode() / yapf_free_buffer(): encode to memory; yapf_save uses it
- yapf.c also compiles as C++
- `yapf compare`: size and decode speed of the original format vs YAPF,
  with a lossless check
- bindings with tested examples: C++ (header-only), C# (P/Invoke),
  Rust (crate, builds the C code), Go (cgo), Java (FFM API, Java 22+),
  Zig (@cImport), LuaJIT (FFI), TypeScript types for the JS port;
  Python now encodes in memory
- docs/LANGUAGES.md and examples/ with measured results
- KDE Dolphin thumbnail plugin (KF6, CMake)
- README: honest status for Photoshop / VS Code / Figma (not run in the
  apps yet) and macOS (cross-compiled only), platform table

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

bindings/cpp/README.md

@@ -0,0 +1,18 @@
+# YAPF for C++
+
+`yapf.hpp` is a header-only C++17 wrapper: RAII, exceptions, `std::vector`.
+Add `../../yapf.c` to your project and include the header.
+
+```cpp
+#include "yapf.hpp"
+
+yapf::Image img = yapf::Image::load("texture.yapf");     // or Image::decode(bytes)
+upload(img.width(), img.height(), img.channels(), img.pixels());
+
+std::vector<uint8_t> file = yapf::Image(256, 256, 4, rgba).encode();
+```
+
+`yapf.c` compiles as C or as C++, so you can simply add it to a C++ project
+(Visual Studio, CMake, …).
+
+Example: `g++ -O2 -std=c++17 example.cpp -x c++ ../../yapf.c -o example -pthread && ./example`