Add Gopher (RFC 1436) as a co-located protocol service, following the
internal/news pattern. Two surfaces share one read-only Resolve engine:
- Public Gopher on :70 (RFC 1436) for any gopher client (lynx, Lagrange).
Classic gopher is stateless with no auth verb, so this surface serves
only public content.
- `ssh gopher@` = "hedgehog": the same gopher wire semantics carried over
the authenticated SSH channel (the member's key is the credential), so it
additionally reaches members-only selectors. Gopher where gopher can,
our own gopher-like thing over SSH where it can't.
Menus surface the member directory + homepages (public_html), an About page
(brand + MOTD), public newsgroups (allowlisted on :70, all groups on
hedgehog), and members' public files. Selectors are confined to each member's
area (path-traversal guarded). New AGENTBBS_GOPHER* env vars; docs/gopher.md
and README updated (incl. the setcap note for binding privileged :70).
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
