updated as per the review comments

pkg/plugin/implementation/signer/cmd/plugin.go

@@ -21,4 +21,4 @@ func (p SignerProvider) New(ctx context.Context, config map[string]string) (defi
 }
 
 // Provider is the exported symbol that the plugin manager will look for.
-var Provider definition.SignerProvider = SignerProvider{}
+var Provider = SignerProvider{}

pkg/plugin/implementation/signer/signer.go

@@ -23,7 +23,7 @@ type Signer struct {
 func New(ctx context.Context, config *Config) (*Signer, func() error, error) {
 	s := &Signer{config: config}
 
-	return s, s.Close, nil
+	return s, nil, nil
 }
 
 // hash generates a signing string using BLAKE-512 hashing.
@@ -70,8 +70,3 @@ func (s *Signer) Sign(ctx context.Context, body []byte, privateKeyBase64 string,
 
 	return base64.StdEncoding.EncodeToString(signature), nil
 }
-
-// Close releases resources (mock implementation returning nil).
-func (s *Signer) Close() error {
-	return nil
-}