Per-app end-user table for the v1.1.8 users::* SDK. Distinct from
admin_users (control-plane operators) — same Argon2id password hash
shape but everything else (uniqueness scope, ownership, lifecycle)
independent.
- Uniqueness on (app_id, lower(email)) — case-insensitive within an
app; same email may exist across two apps.
- AppUserRepository trait + Postgres impl; every method takes app_id
explicitly so cross-app reads are unmistakable at the call site
(matches v1.1.3 cross-app discipline).
- Public AppUserRow never includes the password hash; the credentials
shape is its own struct returned only by the login lookup.
- Cursor-based list keyed on (created_at, id).
- Reserved a timing-flat dummy Argon2id PHC constant in auth.rs for
the upcoming login path so the bad-email and good-email branches
share wall-clock cost.
- Added AppUserId + InvitationId id types in shared::ids.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
