feat(iace): Sprint 4D — Failure Mode Layer (FMEA-Faehigkeit)

150 Failure Modes in 11 ComponentTypes:
- Sensor (20): Signalverlust, Drift, Falschmeldung, Encoder-spezifisch
- Controller (20): Watchdog, Speicher, Bus, Safety-SPS CCF, Antrieb
- Actuator (15): Blockiert, Ueberlast, Haltekraftverlust, Schuetz verschweisst
- Mechanical (20): Ermuedungsbruch, Lagerschaden, Kettenriss, Werkzeugbruch
- Electrical (15): Isolation, Kurzschluss, Erdschluss, Lichtbogen
- Software (15): Exception, Race Condition, Buffer Overflow, Timing
- Hydraulic/Pneumatic (15): Schlauchplatzer, Ventil blockiert, Kavitation
- Safety Device (15): Failure-to-trip, CCF, Bremsenverschleiss, PL-Degradation
- Network (10): Paketverlust, Latenz, Man-in-the-Middle
- AI/ML (5): Model Drift, Adversarial Input, Bias

Architektur:
- FailureModeEntry Struct mit FMEA-Scores (Severity/Occurrence/Detection 1-10)
- RPZ = S x O x D (max 1000, Schwelle >= 100 = Massnahme erforderlich)
- RequiredFailureModes auf HazardPattern fuer FM-gesteuertes Pattern-Matching
- MatchInput.FailureModes + MatchReason "failure_mode" (Explainability)
- GET /failure-modes?component_type= API-Endpoint

10 Tests: Count, UniqueIDs, ValidTypes, NonEmpty, Distribution, RPZ (3x), NilFires, RPZDistribution

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

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

@@ -86,6 +86,31 @@ func (h *IACEHandler) ListProtectiveMeasures(c *gin.Context) {
 	})
 }
 
+// ListFailureModes handles GET /failure-modes
+// Returns the failure mode library, optionally filtered by ?component_type.
+func (h *IACEHandler) ListFailureModes(c *gin.Context) {
+	componentType := c.Query("component_type")
+
+	all := iace.GetFailureModeLibrary()
+
+	var filtered []iace.FailureModeEntry
+	for _, entry := range all {
+		if componentType != "" && entry.ComponentType != componentType {
+			continue
+		}
+		filtered = append(filtered, entry)
+	}
+
+	if filtered == nil {
+		filtered = []iace.FailureModeEntry{}
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"failure_modes": filtered,
+		"total":         len(filtered),
+	})
+}
+
 // ValidateMitigationHierarchy handles POST /projects/:id/validate-mitigation-hierarchy
 // Validates if the proposed mitigation type follows the 3-step hierarchy principle.
 func (h *IACEHandler) ValidateMitigationHierarchy(c *gin.Context) {