frontend phase 1: auth — phone-OTP login, role routing & session refresh

Replace the username/password stub with Balinyaar's real credential (phone-OTP)
and add the role router every authenticated screen sits behind.

- services/auth rewritten for OTP over the b2 contract: types/keys/constants,
  clientApi+mockApi behind a config'd seam, hooks (useRequestOtp/useVerifyOtp/
  useMe/useRefresh/useLogout/useSelectRole/useSessionRoleSync). Stub removed.
- A1/A2 customer login + B1/B2 nurse switch as one OTP flow at /login
  (PhoneStep/OtpStep: auto-verify, resend countdown, wrong/expired/lockout states).
- Role router: pure resolveRoleDestination + RoleRouter -> family / nurse /
  admin / select-role, with a splash while /me loads (no wrong-shell flash).
- SelectRole first-use screen at /select-role.
- Widened AuthState (roles via SessionUser), hydrated from /me by useSessionRoleSync.
- Fetch-layer silent token refresh (single-flight + one retry) + shared
  persistAuthTokens/clearAuthTokens; useRefresh as the on-demand path.
- auth i18n namespace in both locales; tests for routing branches, countdown,
  OtpStep state machine, RoleRouter branches; fixed jest @/ -> src alias.
- Docs: client/CLAUDE.md, frontend STATUS/report, for-backend REQ-002..004.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

dev/shared-working-context/frontend/requests/for-backend.md

@@ -30,3 +30,34 @@ delivers fixes in its own change. **Frontend never edits backend code to "fix" a
 - **Proposed shape:** `{ isSuccess: boolean, statusCode: number, message?: string, requestId?: string, data?: T }`
   and `data: { items: T[], total: number, page: number, pageSize: number }` for lists.
 - **Status:** open
+
+## REQ-002 — OTP length + expiry in RequestOtpResult — filed by frontend-phase-1-b2 — 2026-07-02
+- **Need:** Add `codeLength` (int) and `expiresInSeconds` (int) to `RequestOtpResult`.
+- **Why:** The A2/B2 OTP screen renders one box per digit and (later) a code-expiry hint. `RequestOtpResult`
+  currently exposes only `otpSent` + `resendAvailableInSeconds`, so the frontend hardcodes the box count
+  (`OTP_CODE_LENGTH = 6`, inferred from the live 6-digit verify example, not the 4-box wireframe). Surfacing
+  the length makes the box count contract-driven; the expiry lets us show "code expires in …".
+- **Proposed shape:** `{ otpSent: boolean, resendAvailableInSeconds: number, codeLength: number, expiresInSeconds: number }`
+- **Status:** open
+
+## REQ-003 — Machine-readable error codes for verify_otp failures — filed by frontend-phase-1-b2 — 2026-07-02
+- **Need:** A stable `code` on the 400 envelope for verify_otp that distinguishes wrong code vs expired code
+  vs max-attempts lockout (e.g. `otp_invalid` | `otp_expired` | `otp_locked`), and — for lockout — a
+  `retryAfterSeconds` (or `lockedUntil`) field.
+- **Why:** The OTP screen has explicit **wrong-code**, **expired-code**, and **max-attempts-lockout** states
+  (per the phase spec), but the contract returns the same safe 400 message for all of them, so the frontend
+  can't reliably tell them apart. Today it maps a lockout only when it sees the mock's `otp_locked` code and
+  otherwise degrades to a generic "incorrect or expired" message. A stable machine code (kept generic enough
+  to avoid account enumeration) would let the UI render the precise state + the unlock countdown.
+- **Proposed shape:** `{ isSuccess: false, statusCode: 400, message: "…", code: "otp_locked", data: { retryAfterSeconds: 60 } }`
+- **Status:** open
+
+## REQ-004 — Confirm multi-role disambiguation (activeRole?) — filed by frontend-phase-1-b2 — 2026-07-02
+- **Need:** Confirm whether `MeResult` will gain an `activeRole` (the user's currently-selected actor) for a
+  user who holds **both** `customer` and `nurse`, or whether the client should keep owning that choice.
+- **Why:** The role router must pick one app for a dual-role user. Absent an `activeRole` in the contract,
+  it currently uses the **intended role** carried from the login switch (A1 vs B1), defaulting to the family
+  app. If the backend intends to persist a "current role", the router should prefer it. Also note: verify_otp
+  returns `roles` but no user `id` (only `/me` has it) — fine for now (context id is hydrated from `/me`),
+  flagging in case that changes.
+- **Status:** open