[Distribution] Policy: stores, sideload, and mirrors

[chtnnh]

Parent

Part of #79 (app distribution). Discussion / decision tracking — not an implementation PR by itself.

Summary

PROPOSAL.md already asks whether an app-store listing is a chokepoint. We have no written policy for Play Store, F-Droid, sideload-only, or third-party mirrors. That blocks signing choices (Play App Signing vs self-held key) and what the download page promises.

Questions for maintainers

• Google Play: yes / later / never (and why)
• F-Droid or similar: yes / later / never
• Sideload-only GitHub Releases as the primary channel?
• Allowed mirrors (other orgs hosting APKs / guide ZIP-PDF)? Who may use the name?
• Offline guide export (PDF/ZIP of website/) — ship from Pages, Releases, or both?

Done when

• Short policy paragraph in README and/or website
• Signing + Releases work informed by the store decision
• Mirror / naming guidance is explicit enough that forks do not accidentally impersonate “official” builds

Related

#61 (whether Pages hosts binaries), production signing child of #79.