feat(2.0): Phase 0 — Greenfield-Skeleton (FastAPI + React/shadcn)

Backend: FastAPI mit /api/health + /api/models (read-only aus llama-swap
config, Logik aus v1 portiert). Frontend: Vite + React + Tailwind v4 +
shadcn-Style App-Shell mit Cmd+K, Dark-default, PWA-Manifest; Modelle-View
live aus /api/models. Deploy-Geruest (systemd-Unit :9001, build/deploy-
Skripte, NOPASSWD-sudoers, kein Klartext-Passwort).

Verifiziert: Backend-Endpunkte + Frontend-Build + gerenderte Shell.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/routers/health.py

@@ -0,0 +1,17 @@
+"""Health-/Status-Endpoint — schlanker Lebenszeichen-Check für MC 2.0."""
+
+from fastapi import APIRouter
+
+from config import VERSION
+from services import llamaswap
+
+router = APIRouter(prefix="/api")
+
+
+@router.get("/health")
+def health() -> dict:
+    return {
+        "status": "ok",
+        "version": VERSION,
+        "engine_reachable": llamaswap.engine_reachable(),
+    }