feat(scripts): headless DWG parse script

scripts/parse-dwg.mjs parses a DWG in Node with the same acadrust wasm and
Korean-text fixup as the viewer, prints an entity-type summary and can
write the full parseResult JSON. Needs Node >= 22.18 (type stripping for
fixDwgKoreanText.ts).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/parse-dwg.mjs

@@ -0,0 +1,44 @@
+#!/usr/bin/env node
+/**
+ * Parse a DWG in Node — no browser, no Viewer2D. Same acadrust wasm and
+ * Korean-text fixup as src/viewer2d/dwgParser.ts.
+ *
+ * Usage:
+ *   node scripts/parse-dwg.mjs <file.dwg>             # print summary
+ *   node scripts/parse-dwg.mjs <file.dwg> out.json    # also write full parseResult
+ *
+ * Needs Node >= 22.18 (imports fixDwgKoreanText.ts via built-in type stripping).
+ */
+import { readFileSync, writeFileSync } from 'node:fs';
+import { initSync, parse_dwg_json } from '../src/viewer2d/acadrust-dwg/acadrust_dwg.js';
+import { fixDwgKoreanText } from '../src/viewer2d/fixDwgKoreanText.ts';
+
+const [inPath, outPath] = process.argv.slice(2);
+if (!inPath) {
+  console.error('usage: node scripts/parse-dwg.mjs <file.dwg> [out.json]');
+  process.exit(1);
+}
+
+const wasmUrl = new URL('../src/viewer2d/acadrust-dwg/acadrust_dwg_bg.wasm', import.meta.url);
+initSync({ module: readFileSync(wasmUrl) });
+
+const t0 = performance.now();
+const result = fixDwgKoreanText(JSON.parse(parse_dwg_json(readFileSync(inPath))));
+const ms = performance.now() - t0;
+
+const entities = result.entities ?? [];
+const byType = {};
+for (const e of entities) byType[e.type] = (byType[e.type] ?? 0) + 1;
+
+console.log(`file     : ${inPath}`);
+console.log(`version  : ${result.version}`);
+console.log(`parse    : ${ms.toFixed(0)} ms`);
+console.log(`entities : ${entities.length}`);
+console.table(Object.entries(byType).sort((a, b) => b[1] - a[1]).map(([type, count]) => ({ type, count })));
+console.log(`tables   : ${Object.keys(result.tables ?? {}).join(', ')}`);
+if (result.stats) console.log('stats    :', result.stats);
+
+if (outPath) {
+  writeFileSync(outPath, JSON.stringify(result, null, 2));
+  console.log(`wrote    : ${outPath}`);
+}