docs: record the dist2 static-build deploy procedure

This repository has no deploy script or CI: package.json only builds to
dist/ (gitignored), yet dist2/ is committed and is what actually gets
served. The procedure was folklore reconstructed from commit history each
time someone deployed.

Write it down, including the two traps found while deploying fb8f7ca:

- vite's emptyOutDir defaults to true when outDir sits inside the project
  root, so a bare `vite build --outDir dist2` deletes the hand-placed test
  assets in dist2/samples (configBak/, dwg_18.3mb.dwg). Always pass
  --emptyOutDir false.
- npx vite can fail here with `Missing script: "vite"`; call
  ./node_modules/.bin/vite directly.

Also notes the open issues: no build:dist2 script, old hashed bundles
accumulating in dist2/assets, and test fixtures living inside the build
output directory.

Link it from the README issue table.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -109,6 +109,7 @@ Vite `?url` import 로 로드됩니다.
 |------|------|
 | 구형 한글 DWG TEXT 깨짐 (CP949→Latin-1 mojibake) | [`docs/korean-dwg-text-encoding.md`](./docs/korean-dwg-text-encoding.md) |
 | Model + Paper 동시 렌더로 글자 겹침 / Layout 탭 | [`docs/model-paper-space.md`](./docs/model-paper-space.md) |
+| `dist2` 정적 빌드 배포 절차 (공식 배포 스크립트 없음) | [`docs/deploy-dist2-static-build.md`](./docs/deploy-dist2-static-build.md) |
 
 샘플 패치: `fixDwgKoreanText`, `cadSpaces` + Viewer2D 공간 필터, Model/Layout 탭.  
 원본 `hmwebviewer` 반영 절차는 각 문서를 따른다.