deploy: web Studio on isokit.buildfor.life (same pipeline as cnxvinyl.lol)

Gitea Actions workflow builds dist/web (rustup + wasm32 target, prebuilt
wasm-bindgen CLI at the Cargo.lock version, tools/build_web.py) and
publishes it to /var/www/isokit.buildfor.life on s1 with the blog's
two-directory rename swap and the same VPS_* secrets as cnx_vinyl.
deploy/Caddyfile mirrors the vhost applied on s1 (no-cache so the
unversioned wasm glue never goes stale at Cloudflare).

README.md

@@ -59,6 +59,9 @@ python tools/build_web.py                          # -> dist/web/ (static files,
 ```
 
 `dist/web/` runs from any static web server (http or https, not `file://`).
+A live build is at https://isokit.buildfor.life/: every push to `master` that
+touches the engine or the front end rebuilds and deploys it
+(`.gitea/workflows/deploy-web.yml`; server setup in `deploy/Caddyfile`).
 The first visit opens a copy of the demo. Everything the desktop Studio does
 works the same, because the page runs the same engine and answers the same
 requests. In addition:
@@ -144,6 +147,7 @@ viewer/                isokit-view.js/.css: pan, zoom, levels, rotation, tooltip
 studio/                the Studio GUI (served by `isokit studio`, and by the web Studio)
 web/                   web Studio shell: WASM backend for studio.js, projects, folders, zip, code editor
 examples/demo          demo project
+deploy/Caddyfile       the web Studio's vhost on the buildfor.life web server (s1)
 ```
 
 The layers are independent. A Rust program can draw with `isokit-core` alone.