perf: avoid eager formatting in debug log calls (#4929)

relay/channel/claude/relay-claude.go

@@ -949,9 +949,7 @@ func ClaudeHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayI
 	if err != nil {
 		return nil, types.NewError(err, types.ErrorCodeBadResponseBody)
 	}
-	if common.DebugEnabled {
-		println("responseBody: ", string(responseBody))
-	}
+	logger.LogDebug(c, "responseBody: %s", responseBody)
 	handleErr := HandleClaudeResponseData(c, info, claudeInfo, resp, responseBody)
 	if handleErr != nil {
 		return nil, handleErr