YAPF v1: fast byte-aligned format, SIMD, tools and plugins

Format (version 1, replaces the earlier experimental versions):
- per-tile YCoCg-R or subtract-green colour transform, 8-bit modular
- 12 row filters per 8-row band (Left, Gradient, Up-right, Up-average,
  Up 1-8 rows), none with more than a one-add serial dependency
- residuals in groups of 8 at the group's width (w bits x 8 = w bytes),
  4-bit control codes with repeat-previous-width runs chosen by DP
- constant and stored tiles, independent 64x64 tiles, mips, GPU hints
- all sizes validated before decoding; corrupt input is rejected

Library:
- SIMD on by default: SSSE3 (runtime CPUID check; GCC, Clang, MSVC,
  MinGW) and NEON on ARM64; -DYAPF_NO_SIMD for plain C
- yapf_load_memory, yapf_load_mt, yapf_load_memory_mt
- 6-10x faster decoding than PNG (stb_image) on one core; -O2 and -O3
  builds perform the same
- fixes for macOS (sysconf) and the Windows import library exports

Tools and integrations:
- `yapf` CLI: convert PNG/JPG/TGA/BMP/PSD/GIF <-> YAPF, info, bench,
  thumbnail, mips
- JavaScript and Python bindings (byte-identical to the C encoder)
- GIMP 3 plugin: exports the flattened image, optional mipmaps
- Blender extension: import (also as plane), export, drag and drop
- VS Code preview, Figma plugin, Photoshop scripts, Linux MIME type and
  thumbnailer
- Makefile, updated build.sh / build.bat, tools/build_release.sh
- tests/test_yapf.c (784 checks) and bindings/js/test.js

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

extensions/photoshop/Open YAPF.jsx

@@ -0,0 +1,28 @@
+// Open YAPF — opens .yapf images in Photoshop.
+// Copyright 2026 Nexoniarz — Apache License 2.0.
+// Install: copy this folder's .jsx / .jsxinc files (and yapf / yapf.exe)
+// into Photoshop's Presets/Scripts folder; then File > Scripts > Open YAPF.
+
+#target photoshop
+#include "yapf_common.jsxinc"
+
+(function () {
+    var filter = YAPF_IS_WINDOWS ? "YAPF images:*.yapf,All files:*.*"
+                                 : function (f) { return f instanceof Folder || /\.yapf$/i.test(f.name); };
+    var files = File.openDialog("Open YAPF image", filter, true);
+    if (!files) return;
+    if (!(files instanceof Array)) files = [files];
+
+    for (var i = 0; i < files.length; i++) {
+        var tmp = yapfTempFile(".png");
+        if (!yapfRun([files[i].fsName, tmp.fsName], tmp)) {
+            alert("Could not open " + files[i].name + ".\n\n" + YAPF_TOOL_HELP);
+            return;
+        }
+        var doc = app.open(tmp);
+        // The temporary PNG is no longer needed once the document is open;
+        // use File > Scripts > Save as YAPF to write a .yapf again.
+        doc.info.caption = files[i].fsName;
+        tmp.remove();
+    }
+})();