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/js/example.mjs

@@ -0,0 +1,19 @@
+// node example.mjs ../../other/YAPF.YAPF
+import { readFileSync } from 'node:fs';
+import { createRequire } from 'node:module';
+const YAPF = createRequire(import.meta.url)('./yapf.js');
+
+const path = process.argv[2] ?? '../../other/YAPF.YAPF';
+const file = readFileSync(path);
+
+let img = YAPF.decode(file);
+let best = Infinity;                                   // best of 10 decodes
+for (let i = 0; i < 10; i++) {
+  const t = performance.now();
+  img = YAPF.decode(file);
+  best = Math.min(best, performance.now() - t);
+}
+console.log(`${path}: ${img.width}x${img.height}, ${img.channels} channels, decoded in ${best.toFixed(2)} ms (pure JavaScript)`);
+console.log(`file is ${file.length} bytes, ${(100 * file.length / img.pixels.length).toFixed(1)}% of the raw pixels`);
+const again = YAPF.encode(img);
+console.log(`re-encoded: ${again.length} bytes, identical: ${Buffer.compare(Buffer.from(again), file) === 0}`);