Per-user vs system-wide state (the --system flag)

Install location and state location are independent. By default the engine keeps its daemon state per user (macOS: ~/Library/Application Support/saphan and ~/Library/Logs/saphan; Linux: the XDG directories). With the global --system flag — or automatically when running as root — it uses the FHS paths instead: /etc/saphan, /run/saphan, /var/log/saphan.

A system-wide package does not imply system-wide state: packages ship no service units and start nothing. Every server surface — saphan server, saphan serverd, saphan-gateway and saphan-oauth — is started by an explicit verb and manages its own pidfile under the same daemon path ladder; whether they run per-user or system-wide is the --system decision at run time. Nothing on this page ever starts one for you, which is why Central servers: saphan-gateway and saphan-oauth is a section and not a footnote.