Preserve transport error identities

internal/llm/openai_compatible_client.go

@@ -25,6 +25,18 @@ var (
 	ErrMalformedResponse = errors.New("malformed llm response")
 )
 
+type requestFailedError struct {
+	cause error
+}
+
+func (e *requestFailedError) Error() string {
+	return ErrRequestFailed.Error()
+}
+
+func (e *requestFailedError) Unwrap() []error {
+	return []error{ErrRequestFailed, e.cause}
+}
+
 type OpenAICompatibleConfig struct {
 	BaseURL    string
 	Model      string
@@ -130,7 +142,7 @@ func (c *OpenAICompatibleClient) Generate(ctx context.Context, req domain.Genera
 
 	httpResp, err := httpClient.Do(httpReq)
 	if err != nil {
-		return nil, fmt.Errorf("%w: %v", ErrRequestFailed, err)
+		return nil, &requestFailedError{cause: err}
 	}
 	defer httpResp.Body.Close()