Feat: Frontend-Overhaul E — Lane-Editor, Routing-Policy (hot-reload) & Latenz-Karte

Teil 1: VoiceLatencyCard auf dem Dashboard (GET /api/voice/metrics, C2) —
zeigt STT/Vision/Chat-TTFB/TTS mit p50/p95/last + count.

Teil 2: UI-editierbare Routing-Policy. Neuer routing_policy.py (hot-reload JSON
unter MODELS_DIR/mc2-routing.json, Env=Defaults, atomarer Write, Validierung).
router_logic, gateway_proxy und gateway.routing_summary lesen jetzt live via
load_policy(); routing_summary ist lane-bewusst (chat/coding statt altem auto).
Neue Endpoints GET/PUT /api/routing/policy.

Teil 3: LaneEditor.tsx als ZONE im Cockpit (chat/coding-Aliase + Schwellen +
fast_no_think, Speichern/Default-je-Feld); Gateway-Node zeigt die Lanes.

Verifiziert: npm run build (tsc strict) clean, FastAPI TestClient (GET/PUT,
Validierung, Persistenz, Hot-reload durch die API), venv-Smoke (Routing).

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

backend/services/gateway.py

@@ -6,20 +6,36 @@ LiteLLM-Dienst nötig (baut auf Python 3.14 nicht); bleibt später austauschbar.
 
 from config import PORT
 from services.llamaswap import engine_reachable
-from services.router_logic import FAST, HEAVY, HEAVY_CHARS
+from services.routing_policy import load_policy
 
 
 def routing_summary() -> dict:
+    p = load_policy()
+    coding_default = p["coder_lite"] or p["coder"]
     return {
         "mode": "builtin",
         "endpoint": f":{PORT}/v1  (OpenAI-kompatibel)",
+        # Virtuelle Lanes, die Clients/IDEs als „Modell" wählen (Router pickt das echte Alias).
+        "lanes": [
+            {
+                "name": "chat",
+                "aka": "auto",
+                "target": f"{p['fast']} ↔ {p['heavy']} (nach Komplexität)",
+                "threshold_chars": p["heavy_chars"],
+            },
+            {
+                "name": "coding",
+                "target": f"{coding_default} ↔ {p['coder']} (Eskalation)",
+                "escalate_chars": p["coding_escalate_chars"],
+            },
+        ],
+        # Rückwärtskompatible Flach-Liste (alte UI/Clients).
         "routes": [
-            {"name": "auto", "target": f"{FAST} ↔ {HEAVY} (nach Komplexität)"},
-            {"name": FAST, "target": "llama-swap-Alias 'fast'"},
-            {"name": HEAVY, "target": "llama-swap-Alias 'heavy'"},
+            {"name": "chat", "target": f"{p['fast']} ↔ {p['heavy']} (nach Komplexität)"},
+            {"name": "coding", "target": f"{coding_default} ↔ {p['coder']} (Eskalation)"},
             {"name": "<alias>", "target": "llama-swap-Passthrough (lädt bei Bedarf)"},
         ],
-        "heavy_threshold_chars": HEAVY_CHARS,
+        "heavy_threshold_chars": p["heavy_chars"],
         "fallbacks": [],
         "context_window_fallbacks": [],
     }