feat: signed releases, release feed, notification (read-only)

internal/domain/update/updateRepositoryInterface.go

@@ -0,0 +1,10 @@
+package update
+
+type ReleaseFeed interface {
+	Latest() (Release, error)
+}
+
+type StatusStore interface {
+	Load() (CheckResult, bool)
+	Save(result CheckResult) error
+}