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/vscode/extension.js

@@ -0,0 +1,65 @@
+// YAPF image preview for VS Code — a read-only custom editor for *.yapf.
+// Copyright 2026 Nexoniarz — Apache License 2.0.
+const vscode = require('vscode');
+
+class YapfPreviewProvider {
+  constructor(context) { this.context = context; }
+
+  openCustomDocument(uri) { return { uri, dispose() {} }; }
+
+  async resolveCustomEditor(document, panel) {
+    const media = vscode.Uri.joinPath(this.context.extensionUri, 'media');
+    panel.webview.options = { enableScripts: true, localResourceRoots: [media] };
+    panel.webview.html = this.html(panel.webview, media);
+
+    const send = async () => {
+      try {
+        const bytes = await vscode.workspace.fs.readFile(document.uri);
+        panel.webview.postMessage({ type: 'file', name: document.uri.path.split('/').pop(), bytes });
+      } catch (e) {
+        panel.webview.postMessage({ type: 'error', message: String(e.message || e) });
+      }
+    };
+    panel.webview.onDidReceiveMessage((m) => { if (m.type === 'ready') send(); });
+
+    // Reload when the file changes on disk.
+    const folder = vscode.Uri.joinPath(document.uri, '..');
+    const name = document.uri.path.split('/').pop();
+    const watcher = vscode.workspace.createFileSystemWatcher(new vscode.RelativePattern(folder, name));
+    watcher.onDidChange(send);
+    panel.onDidDispose(() => watcher.dispose());
+  }
+
+  html(webview, media) {
+    const uri = (f) => webview.asWebviewUri(vscode.Uri.joinPath(media, f));
+    const nonce = Math.random().toString(36).slice(2) + Date.now().toString(36);
+    return `<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta http-equiv="Content-Security-Policy"
+      content="default-src 'none'; img-src ${webview.cspSource} data: blob:; style-src ${webview.cspSource}; script-src 'nonce-${nonce}';">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<link rel="stylesheet" href="${uri('preview.css')}">
+<title>YAPF Preview</title>
+</head>
+<body>
+<div id="bar"><span id="info">Loading…</span><span id="controls"></span></div>
+<div id="stage"><canvas id="canvas"></canvas></div>
+<div id="error" hidden></div>
+<script nonce="${nonce}" src="${uri('yapf.js')}"></script>
+<script nonce="${nonce}" src="${uri('preview.js')}"></script>
+</body>
+</html>`;
+  }
+}
+
+function activate(context) {
+  context.subscriptions.push(vscode.window.registerCustomEditorProvider(
+    'yapf.preview', new YapfPreviewProvider(context),
+    { webviewOptions: { retainContextWhenHidden: true }, supportsMultipleEditorsPerDocument: true }));
+}
+
+function deactivate() {}
+
+module.exports = { activate, deactivate };