feat: activity log backend foundation

internal/domain/audit/auditRepositoryInterface.go

@@ -0,0 +1,16 @@
+package audit
+
+import "time"
+
+type Repository interface {
+	Append(event Event) (Event, error)
+	List(filter Filter) (Page, error)
+	Summary(query SummaryQuery) (Summary, error)
+	DeleteOlderThan(cutoff time.Time) (int, error)
+}
+
+type SettingsRepository interface {
+	Get() (Settings, error)
+	SaveRetention(days int) error
+	SaveLastCleanup(at time.Time, removed int) error
+}