perf: N+1 Query Fix — ListHazards 231x schneller

Ersetzt 231 einzelne DB-Queries durch 1 Batch-Query mit
DISTINCT ON (hazard_id) JOIN. Ladezeit von ~40s auf <1s.

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

ai-compliance-sdk/internal/api/handlers/iace_handler_hazards.go

@@ -148,19 +148,19 @@ func (h *IACEHandler) ListHazards(c *gin.Context) {
 		hazards = []iace.Hazard{}
 	}
 
-	// Enrich hazards with latest risk assessment
+	// Enrich hazards with latest risk assessment (single batch query instead of N+1)
 	type enrichedHazard struct {
 		iace.Hazard
 		RiskAssessment interface{} `json:"risk_assessment"`
 	}
 
+	assessmentMap, _ := h.store.GetLatestAssessmentsByProject(c.Request.Context(), projectID)
+
 	enriched := make([]enrichedHazard, len(hazards))
 	for i, hz := range hazards {
 		enriched[i] = enrichedHazard{Hazard: hz}
-		// Get latest assessment for this hazard
-		assessments, err := h.store.ListAssessments(c.Request.Context(), hz.ID)
-		if err == nil && len(assessments) > 0 {
-			enriched[i].RiskAssessment = assessments[len(assessments)-1]
+		if ra, ok := assessmentMap[hz.ID]; ok {
+			enriched[i].RiskAssessment = ra
 		}
 	}