feat(2.0): Phase 1 — Engine + Routing (Herzstueck)

Backend-Services: fit/caps/sources (portiert), discover (live HF + Fit +
Caps + ranked recommendation), llama-swap write/register + groups (Ko-
Residenz swap:false), LiteLLM-Gateway-Config + gateway-Service (model:auto +
Fallbacks). Router: discover/fit/register/groups/routing; health zeigt
gateway_reachable. Frontend: Modelle&Routing mit Caps-Chips, Fit-Badges,
Discover-Tab (live), Routing-View.

Lokal verifiziert: Backend-Smoke (alle Endpunkte) + Frontend-Build +
Browser (Shell, Discover, Caps/Fit). Box-Verifikation offen.

Docs: README + docs/STATUS.md (Phasen-Tracker + Resume-Guide).

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

backend/routers/health.py

@@ -3,7 +3,7 @@
 from fastapi import APIRouter
 
 from config import VERSION
-from services import llamaswap
+from services import gateway, llamaswap
 
 router = APIRouter(prefix="/api")
 
@@ -14,4 +14,5 @@ def health() -> dict:
         "status": "ok",
         "version": VERSION,
         "engine_reachable": llamaswap.engine_reachable(),
+        "gateway_reachable": gateway.gateway_reachable(),
     }