Separate JSON API backend (vm_api.py) + React+TanStack frontend scaffold

- vm_api.py: pure FastAPI JSON API on :8098 with CORS
- vm-api.service: systemd unit for API (replaces inline HTML vm_web.py for frontend)
- vm_web.py: kept intact as fallback; Apache now proxies /api/ -> :8098
- frontend/: Vite + React + TanStack Query scaffold
- Apache vhost updated: DocumentRoot -> frontend/dist, /api/ proxy, SPA fallback
- All original HTML pages still functional via :8099 during transition

frontend/node_modules/@babel/code-frame/README.md

@@ -0,0 +1,19 @@
+# @babel/code-frame
+
+> Generate errors that contain a code frame that point to source locations.
+
+See our website [@babel/code-frame](https://babeljs.io/docs/babel-code-frame) for more information.
+
+## Install
+
+Using npm:
+
+```sh
+npm install --save-dev @babel/code-frame
+```
+
+or using yarn:
+
+```sh
+yarn add @babel/code-frame --dev
+```