feat(iace): expandable detail comparison in benchmark tab

Backend: HazardSummary now includes description, scenario, possible_harm,
trigger_event, and mitigations[] for side-by-side comparison.

Frontend: Each matched pair row is now clickable/expandable showing
two-column detail view:
- Left (GT): hazard type, cause, zone, lifecycle phases, risk values
  (F/W/P/S->R), residual risk, measures, type (KM/TM/BI), norms, comment
- Right (Engine): name, scenario, zone, possible harm, trigger, measures

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

ai-compliance-sdk/internal/iace/benchmark_matcher.go

@@ -59,13 +59,24 @@ func CompareBenchmark(gt *GroundTruth, hazards []Hazard, mitigations []Mitigatio
 		return &BenchmarkResult{}
 	}
 
+	// Build mitigation names per hazard
+	mitNamesByHazard := make(map[string][]string)
+	for _, m := range mitigations {
+		mitNamesByHazard[m.HazardID.String()] = append(mitNamesByHazard[m.HazardID.String()], m.Name)
+	}
+
 	engineSummaries := make([]HazardSummary, len(hazards))
 	for i, h := range hazards {
 		engineSummaries[i] = HazardSummary{
-			ID:       h.ID.String(),
-			Name:     h.Name,
-			Category: h.Category,
-			Zone:     h.HazardousZone,
+			ID:           h.ID.String(),
+			Name:         h.Name,
+			Category:     h.Category,
+			Zone:         h.HazardousZone,
+			Description:  h.Description,
+			Scenario:     h.Scenario,
+			PossibleHarm: h.PossibleHarm,
+			TriggerEvent: h.TriggerEvent,
+			Mitigations:  mitNamesByHazard[h.ID.String()],
 		}
 	}