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/blender/build.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+"""
+Package the Blender extension:  python3 extensions/blender/build.py [libs_dir]
+
+Writes dist/yapf_image-blender.zip, ready for Blender's
+Edit > Preferences > Get Extensions > Install from Disk.
+
+libs_dir (optional) holds prebuilt libraries as <platform>/<file>, e.g.
+linux-x64/libyapf.so, windows-x64/yapf.dll, macos-arm64/libyapf.dylib
+(tools/build_libs.sh makes them).  Without libraries the extension still
+imports .yapf files using numpy, but cannot export.  If no libs_dir is
+given, a library for this machine is built with `cc` when available.
+"""
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+import zipfile
+
+ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+SRC = os.path.join(ROOT, "extensions", "blender", "yapf_image")
+sys.path.insert(0, os.path.join(ROOT, "bindings", "python"))
+import yapf  # noqa: E402  (for the platform folder name)
+
+
+def host_lib(tmp):
+    name = {"win32": "yapf.dll", "darwin": "libyapf.dylib"}.get(sys.platform, "libyapf.so")
+    out = os.path.join(tmp, yapf._platform_dir(), name)
+    os.makedirs(os.path.dirname(out), exist_ok=True)
+    cc = shutil.which("cc") or shutil.which("gcc") or shutil.which("clang")
+    if not cc:
+        return None
+    cmd = [cc, "-O2", "-std=c99", "-shared", "-fPIC", os.path.join(ROOT, "yapf.c"), "-o", out, "-pthread"]
+    return tmp if subprocess.call(cmd) == 0 else None
+
+
+def main():
+    tmp = tempfile.mkdtemp()
+    libs = sys.argv[1] if len(sys.argv) > 1 else host_lib(tmp)
+    os.makedirs(os.path.join(ROOT, "dist"), exist_ok=True)
+    out = os.path.join(ROOT, "dist", "yapf_image-blender.zip")
+    with zipfile.ZipFile(out, "w", zipfile.ZIP_DEFLATED) as z:
+        for f in ("__init__.py", "blender_manifest.toml"):
+            z.write(os.path.join(SRC, f), f)
+        z.write(os.path.join(ROOT, "bindings", "python", "yapf.py"), "yapf.py")
+        z.write(os.path.join(ROOT, "LICENSE"), "LICENSE")
+        if libs:
+            for plat in sorted(os.listdir(libs)):
+                for f in sorted(os.listdir(os.path.join(libs, plat))):
+                    if f.endswith((".so", ".dll", ".dylib")):
+                        z.write(os.path.join(libs, plat, f), "lib/%s/%s" % (plat, f))
+                        print("  bundled lib/%s/%s" % (plat, f))
+    shutil.rmtree(tmp, ignore_errors=True)
+    print("wrote", out)
+
+
+if __name__ == "__main__":
+    main()