raposza/tools: FIRST_INSTALL.md

<!-- Copyright (c) 2026 bentzn --> <!-- SPDX-License-Identifier: Apache-2.0 --> <!-- Author Claude/bentzn Generated 2026-10-12T07:03:15Z Updated 2026-10-16T07:10:00Z --> # First installation — Linux and Windows From a clean machine to a running Sandbox and Workbench. You install Java and download Ra