Document llm NewClient logger help

internal/llm/client.go

@@ -58,7 +58,8 @@ type Client struct {
 }
 
 // NewClient creates a client from cfg. If cfg.Timeout is empty, requests have a
-// five-minute timeout. log must be non-nil.
+// five-minute timeout. log must be non-nil; pass
+// slog.New(slog.DiscardHandler) to run without logs.
 func NewClient(cfg Config, log *slog.Logger) (*Client, error) {
 	if err := cfg.Validate(); err != nil {
 		return nil, fmt.Errorf("invalid config: %w", err)