fix: chat stream resp error (#259)

stream.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"context"
 	"errors"
+	"net/http"
 )
 
 var (
@@ -43,6 +44,9 @@ func (c *Client) CreateCompletionStream(
 	if err != nil {
 		return
 	}
+	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusBadRequest {
+		return nil, c.handleErrorResp(resp)
+	}
 
 	stream = &CompletionStream{
 		streamReader: &streamReader[CompletionResponse]{