feat(iace): add hazard-matching-engine with component library, tag system, and pattern engine

Implements Phases 1-4 of the IACE Hazard-Matching-Engine:
- 120 machine components (C001-C120) in 11 categories
- 20 energy sources (EN01-EN20)
- ~85 tag taxonomy across 5 domains
- 44 hazard patterns with AND/NOT matching logic
- Pattern engine with tag resolution and confidence scoring
- 8 new API endpoints (component-library, energy-sources, tags, patterns, match/apply)
- Completeness gate G09 for pattern matching
- 320 tests passing (36 new)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -980,6 +980,11 @@ func (s *Store) ListMitigations(ctx context.Context, hazardID uuid.UUID) ([]Miti
 	return mitigations, nil
 }
 
+// GetMitigation fetches a single mitigation by ID.
+func (s *Store) GetMitigation(ctx context.Context, id uuid.UUID) (*Mitigation, error) {
+	return s.getMitigation(ctx, id)
+}
+
 // getMitigation is a helper to fetch a single mitigation by ID
 func (s *Store) getMitigation(ctx context.Context, id uuid.UUID) (*Mitigation, error) {
 	var m Mitigation