feat: add initial version of xd2fig tool

tools/inspect-fig.js

@@ -0,0 +1,14 @@
+import fs from 'node:fs';
+import { readCanvas, prettyPrintSchema } from '../src/figfile.js';
+const [,, canvasPath, outDir] = process.argv;
+const r = readCanvas(new Uint8Array(fs.readFileSync(canvasPath)));
+console.log('version', r.version, 'codecs', r.codecs, 'extra chunks', r.extraChunks.length);
+fs.mkdirSync(outDir, { recursive: true });
+fs.writeFileSync(`${outDir}/schema.kiwi.txt`, prettyPrintSchema(r.schema));
+const replacer = (k, v) => v instanceof Uint8Array ? `<bytes ${v.length}>` : v;
+fs.writeFileSync(`${outDir}/message.json`, JSON.stringify(r.message, replacer, 1));
+const m = r.message;
+console.log('message keys', Object.keys(m), 'type', m.type, 'nodes', m.nodeChanges?.length, 'blobs', m.blobs?.length);
+const types = {};
+for (const n of m.nodeChanges) types[n.type] = (types[n.type] || 0) + 1;
+console.log(types);