fix: correct API endpoint paths against Cernion OpenAPI spec

- Add missing /api prefix to all endpoint calls
- Replace hallucinated endpoints with valid OpenAPI paths
- Remove non-existent endpoints (fallback to demo data)
- Lauf 6: /finance/mieterstrom/scenarios removed (never existed)
- Lauf 5: /flex/assets -> /api/flex/devices
- Lauf 5: /flex/schedule/day-ahead -> /api/forecast/schedule/day-ahead
- Lauf 7: /redispatch/* -> /api/redispatch/audits
- Lauf 4: /vdmi/status -> /api/vdmi
- All EDM endpoints prefixed with /api

Author: Rhajaina Agent

api.js

@@ -74,11 +74,11 @@ class CernionAPI {
     } catch (e) { e.isCORS = e.message.indexOf('Failed') >= 0; throw e; }
   }
   async getFlexAssets() {
-    try { return await this.get('/flex/assets'); }
+    try { return await this.get('api/flex/devices'); }
     catch (e) { return { assets: DEMO_ASSETS }; }
   }
   async getFlexSchedule() {
-    try { return await this.get('/flex/schedule/day-ahead'); }
+    try { return await this.get('api/forecast/schedule/day-ahead'); }
     catch (e) { return { schedule: DEMO_SCHEDULE }; }
   }
 }