fix suggestions by coderabbit

Author: WhammyLeaf

config.go

@@ -318,7 +318,12 @@ func FromEnv() (*Config, error) {
 	}
 
 	jwtSecret := getEnv("JWT_SECRET", "")
-	scopes := strings.Split(getEnv("OIDC_SCOPES", ""), " ")
+
+	scopes := []string{}
+	scopesEnv := getEnv("OIDC_SCOPES", "")
+	if scopesEnv != "" {
+		scopes = strings.Split(scopesEnv, " ")
+	}
 
 	return NewConfigBuilder().
 		WithMode(getEnv("OAUTH_MODE", "")).

metadata.go

@@ -282,7 +282,7 @@ func (h *OAuth2Handler) GetAuthorizationServerMetadata() map[string]interface{}
 			"grant_types_supported":                 []string{"authorization_code"},
 			"token_endpoint_auth_methods_supported": []string{"none"},
 			"code_challenge_methods_supported":      []string{"plain", "S256"},
-			"scopes_supported":                      []string{"openid", "profile", "email"},
+			"scopes_supported":                      h.config.Scopes,
 		}
 
 		// Add provider-specific endpoints