Centralize digest validation in public bundle API

internal/bundle/digest.go

@@ -1,19 +1,9 @@
 package bundle
 
-import (
-	"fmt"
-	"regexp"
-
-	publicbundle "gitea.maximumdirect.net/eric/distributor/pkg/bundle"
-)
-
-var digestPattern = regexp.MustCompile(`^sha256:[0-9a-f]{64}$`)
+import publicbundle "gitea.maximumdirect.net/eric/distributor/pkg/bundle"
 
 func ValidateDigest(value string) error {
-	if !digestPattern.MatchString(value) {
-		return fmt.Errorf("must be lowercase sha256:<64 hex>")
-	}
-	return nil
+	return publicbundle.ValidateDigest(value)
 }
 
 func FileDigest(data []byte) string {