RFC: Host identity and version via System.host_info

[filvecchiato]

Source PR: #177 · docs/rfcs/host-info.md · @valentinfernandez1

Description

System::host_info reports the host's platform, name and version. It is always available: no session, no prompt.

Motivation

Nothing on the wire identifies the host today, so a product cannot adapt to it and a diagnosis report cannot name the build a failure came from — only a mode guessed from the user agent.

Requirements

• Empty request; the response is HostInfo { platform, name, version }.
• platform is a closed enum (Web, Android, Ios, Desktop, Cli, Unknown); name and version are free-form.
• Answerable before authentication, like handshake.
• Playground and explorer key host rows on the reported triple instead of the user-agent guess.

Tasks

• RFC document body
• Implementation — rust-core
• Implementation — hosts
  • dotli
  • Desktop
  • iOS
  • Android
  • host-cli