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/zig/example.zig

@@ -0,0 +1,33 @@
+// YAPF from Zig: the C header is imported directly.
+//   zig run example.zig ../../yapf.c -I../.. -lc -O ReleaseFast
+// (Uses only the C API plus std.debug.print, so it works across Zig versions.)
+const std = @import("std");
+const c = @cImport({
+    @cInclude("yapf.h");
+    @cInclude("time.h");
+});
+
+pub fn main() !void {
+    const path: [:0]const u8 = "../../other/YAPF.YAPF";
+
+    var img: *c.yapf_image_t = c.yapf_load(path.ptr) orelse return error.CannotLoad;
+    var best: c.clock_t = std.math.maxInt(c.clock_t); // best of 10 decodes
+    for (0..10) |_| {
+        const t = c.clock();
+        const again = c.yapf_load(path.ptr) orelse return error.CannotLoad;
+        best = @min(best, c.clock() - t);
+        c.yapf_free(img);
+        img = again;
+    }
+    defer c.yapf_free(img);
+    std.debug.print("{s}: {d}x{d}, {d} channels, decoded in {d:.2} ms\n", .{
+        path, img.width, img.height, img.channels, @as(f64, @floatFromInt(best)) * 1000.0 / @as(f64, @floatFromInt(c.CLOCKS_PER_SEC)),
+    });
+
+    var data: ?*anyopaque = null;
+    var size: usize = 0;
+    if (c.yapf_encode(img, &data, &size) != c.YAPF_OK) return error.EncodeFailed;
+    defer c.yapf_free_buffer(data);
+    const raw = @as(f64, @floatFromInt(img.width * img.height * img.channels));
+    std.debug.print("encoded: {d} bytes, {d:.1}% of the raw pixels\n", .{ size, 100.0 * @as(f64, @floatFromInt(size)) / raw });
+}