Completes TODO #2. PUBLIC_MODE swaps the ALLOWED_USERS allowlist for a
membership check against REQUIRED_CHATS, with REQUIRE_MODE choosing
between needing every chat or just one.
- Stop is_admin() falling back to "everyone is an admin" when
ADMIN_USERS is unset once PUBLIC_MODE is on. That fallback is the
original single-owner convenience, but under public mode it handed
moderation, /edit and /delete to anyone who found the bot. Public
mode now grants admin to nobody until ADMIN_USERS is set, and says
so at startup. Private deployments are unaffected.
- Cache membership answers: inline search queries on every keystroke,
so an uncached check meant several API calls per typed character.
Grants last five minutes, refusals thirty seconds, so a user who has
just joined is not locked out for the full window.
- Fail closed when the membership check errors, and validate
REQUIRED_CHATS at startup so a chat the bot cannot read is reported
rather than silently refusing every user.
- Refused users get a join prompt with real links instead of silence;
inline shows a tappable bar that opens the bot and explains why.
A private bot stays silent as before.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
goyban