feat: API Key Auth + erweiterte MCP Tools + Dokumentation

- API Key Middleware für alle /api/ Endpoints (X-API-Key, Bearer, Query)
- API Key Management Routes (generate, revoke, status)
- MCP Tools erweitert: 12 Tools (war 3) inkl. bulk ops, dashboard, search
- Audit Logging für alle API/MCP Aktionen
- docs/API-REFERENCE.md - vollständige API Dokumentation
- docs/ARCHITECTURE.md - Architektur-Übersicht
- Vorbereitung für NotiBot-Integration

server/index.ts

@@ -3,6 +3,7 @@ import { registerRoutes } from "./routes.js";
 import { initializeDatabase, closeDatabase } from "./db.js";
 import { storage } from "./storage";
 import { initializeVapid } from "./push.js";
+import { apiKeyAuth } from "./api-key-auth.js";
 
 const app = express();
 app.set("trust proxy", true);