feat(auth): trusted devices, recovery codes, and admin MFA management

Add opt-in "Trust this device" so a browser/app skips the TOTP step (never
the password) for 30 days, single-use bcrypt recovery codes as a 2FA-lockout
fallback, and admin trusted-device/MFA-reset management — backend, web UI,
OpenAPI spec, and tests.

- Schema: trusted_devices (sha256 token hash, looked up by unique index) and
  recovery_codes (bcrypt, single-use). Both additive/idempotent.
- Session service: trust-token mint/hash/resolve + cap helpers; new rg_trust
  httpOnly cookie (survives logout, revoked on untrust/password change/reset/
  TOTP disable). JWTs stay stateless — trust is a server-side row, not a claim.
- Web + mobile login accept a trusted-device token / recovery code; login/totp
  gains trustDevice + recoveryCode. Cap of 10/user with NO silent pruning — an
  over-cap trust returns 409/trustLimitReached and the client prompts to revoke.
- Self-service /auth/me/trusted-devices* + recovery-codes*; admin
  /admin/users/:id/trusted-devices* + /mfa/reset. All actions audit-logged.
- Client: "Trust this device" + recovery-code login options, one-time recovery
  code display, Trusted Devices + Recovery Codes account panels, a TOTP-styled
  revoke-to-continue cap modal, and admin per-user security controls.
- OpenAPI regenerated; 33 new server tests (all suites green).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/contexts/AuthContext.jsx

@@ -38,11 +38,14 @@ export function AuthProvider({ children }) {
     return data
   }, [])
 
-  // Step 2 for TOTP users: exchange the challenge + code for a real session.
-  const loginTotp = useCallback(async (challenge, code) => {
-    const data = await api.loginTotp(challenge, code)
+  // Step 2 for TOTP users: exchange the challenge + a second factor (TOTP code or a
+  // recovery code) for a real session. `extra` carries recoveryCode + the
+  // trustDevice/deviceName opt-in. Returns the full payload ({ user,
+  // trustLimitReached?, devices? }) so the caller can handle the device-cap prompt.
+  const loginTotp = useCallback(async (challenge, code, extra) => {
+    const data = await api.loginTotp(challenge, code, extra)
     setUser(data.user)
-    return data.user
+    return data
   }, [])
 
   // Step 2 for SSO logins whose account has 2FA on. The pending challenge lives in