feat: add audit event domain type and service interface

internal/domain/audit.go

@@ -0,0 +1,21 @@
+package domain
+
+import (
+	"context"
+	"encoding/json"
+)
+
+type AuditEvent struct {
+	UserID        string
+	Action        string
+	ResourceType  string
+	ResourceID    string
+	MetadataJSON  json.RawMessage
+	IP            string
+	UserAgent     string
+}
+
+type AuditService interface {
+	Record(ctx context.Context, event AuditEvent) error
+}
+