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>

examples/README.md

@@ -0,0 +1,62 @@
+# Examples: how fast, how small
+
+## Try it on your own images
+
+```sh
+make                                   # builds build/yapf
+build/yapf compare photo.png ui.png    # any PNG / JPG / TGA / BMP
+```
+
+`yapf compare` encodes each image to YAPF in memory, checks that it decodes
+back to exactly the same pixels, and times decoding the original format
+against YAPF on one core and on all cores:
+
+```
+ui_reverb.png  (261 x 430, RGBA)
+  raw     438.4 KB
+  PNG     176.6 KB   40.3% of raw   decode    2.049 ms
+  YAPF    143.7 KB   32.8% of raw   decode    0.170 ms   12.1x faster, 81% of the PNG size
+  YAPF on all cores: decode 0.176 ms (2.5 GB/s), encode 8 ms, lossless: yes
+```
+
+## Results on a mixed set of images
+
+AMD Ryzen 7 5700G, `make` (gcc -O2), PNG decoded with stb_image.  The test
+images (a 4K wallpaper, UI screenshots, an app icon and seamless textures
+from open-source projects) are not redistributed here; run `yapf compare`
+on your own files to reproduce.
+
+| Image | PNG | YAPF | YAPF / PNG size | PNG decode | YAPF decode | Faster |
+| :---- | --: | ---: | --------------: | ---------: | ----------: | -----: |
+| UI screenshot 261×430 | 176.6 KB | 143.7 KB | **81 %** | 2.05 ms | 0.17 ms | **12×** |
+| UI screenshot 305×529 | 201.5 KB | 185.0 KB | **92 %** | 2.55 ms | 0.24 ms | **11×** |
+| App icon 128×128 | 24.9 KB | 23.1 KB | **93 %** | 0.30 ms | 0.026 ms | **11×** |
+| Wallpaper 3840×2160 | 1.77 MB | 2.21 MB | 125 % | 73.7 ms | 6.8 ms | **11×** |
+| Rock texture 512×512 | 182.6 KB | 221.8 KB | 121 % | 1.64 ms | 0.17 ms | **10×** |
+| Wood texture 512×512 | 185.8 KB | 234.1 KB | 126 % | 1.64 ms | 0.17 ms | **10×** |
+| Canvas texture 512×512 | 171.5 KB | 245.6 KB | 143 % | 1.36 ms | 0.16 ms | **9×** |
+| YAPF logo 512×512 | 60.5 KB | 89.3 KB | 148 % | 1.25 ms | 0.25 ms | **5×** |
+
+In short: **smaller than PNG on UI-style images, 20–50 % larger on photos
+and textures, and 5–12× faster to decode** — always lossless.  The decoder
+reaches 5–6 GB/s on large images on one core, and more with
+`yapf_load_mt`.
+
+## Code examples
+
+| Language | Example |
+| :------- | :------ |
+| C | [`examples/c/example.c`](c/example.c) |
+| C++ | [`bindings/cpp/example.cpp`](../bindings/cpp/example.cpp) |
+| Python | [`bindings/python/example.py`](../bindings/python/example.py) |
+| C# | [`bindings/csharp/Example`](../bindings/csharp/Example) |
+| Rust | [`bindings/rust/examples/demo.rs`](../bindings/rust/examples/demo.rs) |
+| Go | [`bindings/go/example`](../bindings/go/example) |
+| Java | [`bindings/java/Example.java`](../bindings/java/Example.java) |
+| Zig | [`bindings/zig/example.zig`](../bindings/zig/example.zig) |
+| Lua | [`bindings/lua/example.lua`](../bindings/lua/example.lua) |
+| JavaScript | [`bindings/js/example.mjs`](../bindings/js/example.mjs) |
+
+Each one loads a `.yapf` file, prints its size and decode time, re-encodes
+it (byte-identical to the file) and writes a new image from its own pixels.
+See [docs/LANGUAGES.md](../docs/LANGUAGES.md) for setup in each language.