feat: EU AI Database Registration (Art. 49) — Backend + Frontend

Backend (Go):
- DB Migration 023: ai_system_registrations Tabelle
- RegistrationStore: CRUD + Status-Management + Export-JSON
- RegistrationHandlers: 7 Endpoints (Create, List, Get, Update, Status, Prefill, Export)
- Routes in main.go: /sdk/v1/ai-registration/*

Frontend (Next.js):
- 6-Step Wizard: Anbieter → System → Klassifikation → Konformitaet → Trainingsdaten → Pruefung
- System-Karten mit Status-Badges (Entwurf/Bereit/Eingereicht/Registriert)
- JSON-Export fuer EU-Datenbank-Submission
- Status-Workflow: draft → ready → submitted → registered
- API Proxy Routes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ai-compliance-sdk/cmd/server/main.go

@@ -104,6 +104,8 @@ func main() {
 	auditHandlers := handlers.NewAuditHandlers(auditStore, exporter)
 	uccaHandlers := handlers.NewUCCAHandlers(uccaStore, escalationStore, providerRegistry)
 	escalationHandlers := handlers.NewEscalationHandlers(escalationStore, uccaStore)
+	registrationStore := ucca.NewRegistrationStore(pool)
+	registrationHandlers := handlers.NewRegistrationHandlers(registrationStore, uccaStore)
 	roadmapHandlers := handlers.NewRoadmapHandlers(roadmapStore)
 	workshopHandlers := handlers.NewWorkshopHandlers(workshopStore)
 	portfolioHandlers := handlers.NewPortfolioHandlers(portfolioStore)
@@ -284,6 +286,18 @@ func main() {
 			obligationsHandlers.RegisterRoutes(uccaRoutes)
 		}
 
+		// AI Registration routes - EU AI Database (Art. 49)
+		regRoutes := v1.Group("/ai-registration")
+		{
+			regRoutes.POST("", registrationHandlers.Create)
+			regRoutes.GET("", registrationHandlers.List)
+			regRoutes.GET("/:id", registrationHandlers.Get)
+			regRoutes.PUT("/:id", registrationHandlers.Update)
+			regRoutes.PATCH("/:id/status", registrationHandlers.UpdateStatus)
+			regRoutes.POST("/prefill/:assessment_id", registrationHandlers.Prefill)
+			regRoutes.GET("/:id/export", registrationHandlers.Export)
+		}
+
 		// RAG routes - Legal Corpus Search & Versioning
 		ragRoutes := v1.Group("/rag")
 		{