Adds a new GitHub Pages workflow that publishes the ADR-097 three.js
demo gallery alongside the existing observatory/, pose-fusion/,
pointcloud/, and nvsim/ deployments. Uses keep_files: true so the
other deployments are preserved.
What ships:
* `examples/three.js/index.html` — new landing page that lists all 5
demos with screenshots, "standalone" vs "needs FBX" badges, and an
honest note explaining the Mixamo X Bot.fbx license boundary
(demos 04 and 05 need a local download from mixamo.com; demos
01-03 run standalone in any modern browser).
* `.github/workflows/threejs-pages.yml` — staged copy of demos/,
screenshots/, README.md, and the new index.html into
`_site/three.js/`. Drops an `assets/README.txt` placeholder
explaining the FBX-not-shipped policy. Triggered on changes to
examples/three.js/** or the workflow itself.
* README.md — adds the live link to the existing demo row
(`▶ three.js Demos (5)`) plus a one-line callout describing the
gallery and the FBX caveat.
After this PR merges, the workflow runs and publishes:
https://ruvnet.github.io/RuView/three.js/d67d9872c1
f01e29934f
