fix: resolve lint issues for make check compliance

internal/config/config.go

@@ -51,7 +51,7 @@ type Config struct {
 	MaintenanceMode bool
 	MetricsUsername string
 	MetricsPassword string
-	SessionSecret   string
+	SessionSecret   string //nolint:gosec // not a hardcoded credential, loaded from env/file
 	CORSOrigins     string
 	params          *Params
 	log             *slog.Logger