backend phase 2: identity — phone-OTP auth, sessions & roles (REST)

- six REST endpoints (auth/request_otp, verify_otp, refresh, logout, me,
  me/select_role) wrapping the existing JWE/TOTP/RBAC engine
- usr.UserSessions with refresh-token rotation + stolen-token (replay)
  detection → revoke-all + 401; logout rotates the security stamp
- users extended: gender, national_id (enc, NULL until KYC),
  shahkar_verified_at (auto-reset on phone change), phone_hash UNIQUE,
  is_active, deleted_at + soft-delete filter; phone/email/national_id
  encrypted at rest via IFieldEncryptor value converter
- user_roles grant/revoke audit trail + global revoked filter; 7 roles
  seeded; admin sub-roles never self-assignable (403)
- ISmsSender seam (mock logs the OTP code) replaces the TODO log lines
- OperationResult/BaseController learned enveloped 401/403
- auth knobs as platform_configs rows (resend/attempts/session TTL)
- migration IdentitySessionsAndUserExtensions applied to the dev DB
- 24 new tests incl. Baya.Test.Api (WebApplicationFactory over SQLite);
  47 total green, zero new build warnings; swagger snapshot + contract
  (identity-auth.md), handoff, report, mocks-registry updated

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

product/business/01-actors-and-onboarding.md

@@ -11,6 +11,7 @@
   - A **nurse** must complete the full verification pipeline (Section 2) before any of their service variants become bookable. `national_id` is populated only after the identity step passes.
   - An **admin** is provisioned internally with RBAC roles.
 - Each successful login creates a refresh-token session that can be revoked (logout, stolen-token detection).
+- **As-built decisions (backend-phase-2):** each refresh **rotates** the session (old revoked, new pair issued); a refresh token presented against an already-revoked session is treated as **stolen-token reuse → all of the user's sessions are revoked and the call returns 401**. Logout rotates the security stamp, so every outstanding access token dies (other devices recover by refreshing). OTP request/verify never reveal whether a phone already has an account; one OTP per phone per resend window (`auth_otp_resend_seconds`), and after `auth_otp_max_attempts` wrong codes verification refuses until a fresh OTP. `customer`/`nurse` are the only self-selectable roles (a user may hold both; grants audited via `granted_by`/`granted_at`); any admin sub-role self-assign attempt returns **403** — admin provisioning is internal-only.
 
 ## (b) Iran-specific considerations
 - Phone-OTP is the dominant Iranian login norm and is also the anchor for **Shahkar** SIM↔national-ID binding (Section 2).