delete back and frontend

add schafkopf os
add build firmware action

schafkopf-os/README.md

@@ -0,0 +1,27 @@
+# schafkopf-os — Test Frontend (Axum + Askama)
+
+This crate serves a tiny test frontend using Axum + Askama and static assets.
+
+## Run
+
+```bash
+cargo run --manifest-path schafkopf-os/Cargo.toml
+```
+
+Then open:
+
+- http://127.0.0.1:3000 — server renders an Askama template
+- Click "Ping API" to call `GET /api/ping`
+
+Or test the API directly:
+
+```bash
+curl -s http://127.0.0.1:3000/api/ping | jq
+```
+
+## Structure
+
+- `src/main.rs` — Axum server with routes `/` and `/api/ping`, and static files at `/static`
+- `templates/index.html` — Askama template for the homepage
+- `static/styles.css` — Minimal styling
+- `static/app.js` — Browser script to call the ping API