fix(lint): resolve all errcheck violations in ingestion module

ingestion/internal/llm/client.go

@@ -81,7 +81,7 @@ func (c *Client) Complete(ctx context.Context, system, user string) (string, err
 	}
 
 	if resp.StatusCode == http.StatusTooManyRequests {
-		resp.Body.Close()
+		_ = resp.Body.Close()
 		wait := 5 * time.Second
 		if ra := resp.Header.Get("Retry-After"); ra != "" {
 			if secs, err := strconv.Atoi(ra); err == nil {
@@ -98,7 +98,7 @@ func (c *Client) Complete(ctx context.Context, system, user string) (string, err
 			return "", fmt.Errorf("retry LLM call: %w", err)
 		}
 	}
-	defer resp.Body.Close()
+	defer resp.Body.Close() //nolint:errcheck
 
 	out, err := io.ReadAll(resp.Body)
 	if err != nil {