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/java/Example.java

@@ -0,0 +1,29 @@
+// java --enable-native-access=ALL-UNNAMED -Dyapf.library=../../build/libyapf.so Example.java ../../other/YAPF.YAPF
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+
+public class Example {
+    public static void main(String[] args) throws Exception {
+        Path path = Path.of(args.length > 0 ? args[0] : "../../other/YAPF.YAPF");
+        byte[] file = Files.readAllBytes(path);
+
+        Yapf.Image img = Yapf.decode(file);            // first call also loads the library
+        double ms = Double.MAX_VALUE;                  // best of 10, as in a running program
+        for (int i = 0; i < 10; i++) {
+            long t = System.nanoTime();
+            img = Yapf.decode(file);
+            ms = Math.min(ms, (System.nanoTime() - t) / 1e6);
+        }
+        System.out.printf("%s: %dx%d, %d channels, decoded in %.2f ms%n", path, img.width(), img.height(), img.channels(), ms);
+        System.out.printf("file is %d bytes, %.1f%% of the raw pixels%n", file.length, 100.0 * file.length / img.pixels().length);
+
+        byte[] again = Yapf.encode(img);
+        System.out.printf("re-encoded: %d bytes, identical: %b%n", again.length, Arrays.equals(again, file));
+
+        byte[] rgb = new byte[64 * 64 * 3];
+        for (int i = 0; i < rgb.length; i++) rgb[i] = (byte) (i * 3);
+        Yapf.save(Path.of("java.yapf"), new Yapf.Image(64, 64, 3, rgb));
+        System.out.println("wrote java.yapf");
+    }
+}