#7596: docs(gateway): add multi-machine config sync guide

## Summary Adds documentation for syncing OpenClaw config between multiple machines (e.g., home server + laptop) using git while keeping machine-specific gateway settings separate. ## Problem Users with multiple machines often want to: - Keep a server running the gateway 24/7 - Use a laptop that connects remotely when home, but runs locally when traveling - Sync workspaces, sessions, and config via git The challenge: \`gateway.mode\` needs to be \`local\` on the server but \`remote\` on the laptop. A simple git sync overwrites these settings. ## Solution Uses the existing \`\$include\` directive to split machine-specific gateway config into a gitignored file (\`gateway-local.json5\`), while keeping shared settings in the tracked \`openclaw.json\`. ## Documentation Includes - Step-by-step setup for server and laptop - Git configuration with proper ignores - Optional mode-switching scripts for laptops - Troubleshooting common issues (timestamp conflicts, session continuity) - Table of what should/shouldn't be synced ## Related Docs Links to existing docs: - [Configuration](/gateway/configuration) - [Config Includes](/gateway/configuration#config-includes-include) - [Remote Access](/gateway/remote) - [Multiple Gateways](/gateway/multiple-gateways) <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Adds a new Gateway documentation page (`docs/gateway/multi-machine-sync.md`) describing how to sync `~/.openclaw` across multiple machines via git while keeping machine-specific gateway settings separate using `$include`. The doc covers: creating per-machine `gateway-local.json5`, updating `openclaw.json`, suggested `.gitignore` entries, optional mode-switching scripts, an auto-sync cron example, and troubleshooting guidance. This fits into the existing Gateway docs alongside the configuration and remote access guides by providing a practical workflow for multi-host setups. <h3>Confidence Score: 3/5</h3> - Mostly safe to merge, but there’s a likely docs-inaccuracy around `$include` semantics that could misconfigure users. - Only a new documentation file is added, so code risk is low; however, the recommended config structure appears to contradict the documented `$include` replacement behavior, which could lead to broken configs for readers following the guide. - docs/gateway/multi-machine-sync.md (especially the `$include` example/merge explanation and internal anchor link) <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->