- provision_member reuses the stored LiteLLM key instead of minting a duplicate
alias (LiteLLM 400s on member:<email>); fixes re-provisioning of existing members
- store_member preserves an existing slug when none is passed
- add welcome_sent_at + REINVITE_AFTER_DAYS; nightly sweep re-invites
active members who never completed account setup, throttled to 3 days