feat(iace): Sprint 4B — ISO 12100 Hazard/Situation/Harm Trennung

ISO 12100 trennt: Hazard (Quelle) → Hazardous Situation (Person exponiert) → Harm (Verletzung).
Bisher war alles in einem Hazard-Record vermischt.

Implementierung als abgeleitetes Feld (keine DB-Migration noetig):
- HazardType Feld auf Hazard Entity ("hazard"|"hazardous_situation"|"harm")
- DeriveHazardType() berechnet Typ aus Scenario/PossibleHarm/Category
- Explizites Override moeglich (HazardType direkt setzen)
- GeneratedHazardType auf HazardPattern fuer Pattern-gesteuerte Zuweisung
- Store: GetHazard/ListHazards setzen HazardType automatisch
- Init-Handler: Fuellt jetzt TriggerEvent, PossibleHarm, AffectedPerson, HazardousZone
  aus Pattern-Match-Daten (vorher leer gelassen)

6 neue Tests: ScenarioAndHarm, HarmOnly, CategoryOnly, ExplicitOverride,
EmptyFallback, PatternMatchField

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

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

@@ -57,6 +57,37 @@ const (
 	HazardStatusClosed     HazardStatus = "closed"
 )
 
+// HazardType distinguishes ISO 12100 concepts in the hazard chain:
+// Hazard → Hazardous Situation → Harm
+const (
+	HazardTypeHazard             = "hazard"             // Source of potential harm (e.g. rotating shaft)
+	HazardTypeHazardousSituation = "hazardous_situation" // Person exposed to hazard (e.g. operator near shaft)
+	HazardTypeHarm               = "harm"               // Injury outcome (e.g. entanglement)
+	DefaultHazardType            = HazardTypeHazardousSituation
+)
+
+// DeriveHazardType determines the ISO 12100 hazard type from the hazard's fields.
+// If an explicit type is set, it is returned as-is. Otherwise:
+//   - PossibleHarm filled + Scenario filled → "hazardous_situation" (most specific)
+//   - Only PossibleHarm filled → "harm"
+//   - Only TriggerEvent/Category → "hazard" (source only)
+//   - Default fallback → "hazardous_situation"
+func DeriveHazardType(h *Hazard) string {
+	if h.HazardType != "" {
+		return h.HazardType
+	}
+	if h.Scenario != "" && h.PossibleHarm != "" {
+		return HazardTypeHazardousSituation
+	}
+	if h.PossibleHarm != "" && h.Scenario == "" {
+		return HazardTypeHarm
+	}
+	if h.Scenario == "" && h.PossibleHarm == "" && h.Category != "" {
+		return HazardTypeHazard
+	}
+	return DefaultHazardType
+}
+
 // AssessmentType represents the type of risk assessment
 type AssessmentType string