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/Save as YAPF.jsx

@@ -0,0 +1,40 @@
+// Save as YAPF — writes the active document as a .yapf image.
+// Copyright 2026 Nexoniarz — Apache License 2.0.
+// The visible result is saved: a flattened 8-bit RGB (or grayscale) copy,
+// transparency kept.  Your document is not modified.
+
+#target photoshop
+#include "yapf_common.jsxinc"
+
+(function () {
+    if (!app.documents.length) { alert("Open a document first."); return; }
+    var doc = app.activeDocument;
+
+    var base = doc.name.replace(/\.[^.]+$/, "");
+    var start = new File((doc.saved && doc.path ? doc.path.fsName : Folder.desktop.fsName) + "/" + base + ".yapf");
+    var out = start.saveDlg("Save as YAPF", YAPF_IS_WINDOWS ? "YAPF images:*.yapf" : undefined);
+    if (!out) return;
+    if (!/\.yapf$/i.test(out.name)) out = new File(out.fsName + ".yapf");
+    var mips = confirm("Also store mipmaps (for game engines / GPUs)?", true, "YAPF");
+
+    var tmp = yapfTempFile(".png");
+    var copy = doc.duplicate(base + " (YAPF export)", true);     // merged copy
+    try {
+        if (copy.mode !== DocumentMode.RGB && copy.mode !== DocumentMode.GRAYSCALE)
+            copy.changeMode(ChangeMode.RGB);
+        if (copy.bitsPerChannel !== BitsPerChannelType.EIGHT)
+            copy.bitsPerChannel = BitsPerChannelType.EIGHT;
+        var opts = new PNGSaveOptions();
+        opts.interlaced = false;
+        copy.saveAs(tmp, opts, true, Extension.LOWERCASE);
+    } finally {
+        copy.close(SaveOptions.DONOTSAVECHANGES);
+    }
+
+    var args = [tmp.fsName, out.fsName];
+    if (mips) args.push("--mips");
+    var ok = yapfRun(args, out);
+    tmp.remove();
+    if (!ok) { alert("Could not write " + out.name + ".\n\n" + YAPF_TOOL_HELP); return; }
+    alert("Saved " + out.fsName + " (" + Math.round(out.length / 1024) + " KB)");
+})();