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/figma/code.js

@@ -0,0 +1,54 @@
+// YAPF for Figma — plugin main thread (has the document, no DOM).
+// Copyright 2026 Nexoniarz — Apache License 2.0.
+// Decoding/encoding happens in the UI (ui.html), which has a DOM.
+
+figma.showUI(__html__, { width: 380, height: 330, themeColors: true });
+figma.ui.postMessage({ type: 'mode', mode: figma.command || 'import' });
+
+function sendSelection() {
+  const nodes = figma.currentPage.selection.filter((n) => 'exportAsync' in n);
+  figma.ui.postMessage({ type: 'selection', names: nodes.map((n) => n.name) });
+}
+figma.on('selectionchange', sendSelection);
+sendSelection();
+
+figma.ui.onmessage = async (msg) => {
+  if (msg.type === 'import') {
+    // msg.images: [{ name, width, height, png: Uint8Array }]
+    const created = [];
+    const center = figma.viewport.center;
+    let x = center.x;
+    for (const im of msg.images) {
+      try {
+        const image = figma.createImage(im.png);
+        const rect = figma.createRectangle();
+        rect.name = im.name;
+        rect.resize(im.width, im.height);
+        rect.fills = [{ type: 'IMAGE', imageHash: image.hash, scaleMode: 'FILL' }];
+        rect.x = Math.round(x - (created.length ? 0 : im.width / 2));
+        rect.y = Math.round(center.y - im.height / 2);
+        x = rect.x + im.width + 40;
+        figma.currentPage.appendChild(rect);
+        created.push(rect);
+      } catch (e) {
+        figma.notify(im.name + ': ' + (e.message || e) + ' (Figma accepts images up to 4096×4096)', { error: true });
+      }
+    }
+    if (created.length) {
+      figma.currentPage.selection = created;
+      figma.viewport.scrollAndZoomIntoView(created);
+      figma.notify('Imported ' + created.length + ' YAPF image' + (created.length > 1 ? 's' : ''));
+    }
+  }
+
+  if (msg.type === 'export') {
+    const nodes = figma.currentPage.selection.filter((n) => 'exportAsync' in n);
+    if (!nodes.length) { figma.notify('Select one or more layers to export', { error: true }); return; }
+    for (const node of nodes) {
+      const png = await node.exportAsync({ format: 'PNG', constraint: { type: 'SCALE', value: msg.scale || 1 } });
+      figma.ui.postMessage({ type: 'exported', name: node.name, png });
+    }
+  }
+
+  if (msg.type === 'close') figma.closePlugin();
+};