- guild_overview offered an invite link to a full pool bot whenever it was
in ANY server (`if member` tested the non-empty guild_ids list, not
membership of this guild). Now: in this guild, or invitable.
- start_stream re-reads membership once on pool_full as it already does on
no_bot_in_guild, so a full pool bot an admin just invited by hand is found.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>