Gate Stripe readiness on real credentials, surface dead-lettered syncs
as
failed with retry, and add header-safe toast JSON encoding.
Switch the test Keycloak realm references to `test` and document the
OpenSpec change.
Seed Keycloak into a dedicated wikicafe app realm and repoint the
test OIDC, Temporal, and FedWiki wiring to it.
Label test credentials as throwaway, remove the unused realm export from
tracking, and have init write the embedded starter config.
Rewrite the README around purpose, architecture, quickstart, and
status. Add contributing/security policies plus a docs index with
audience front matter across existing docs.
cgalo5758