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/routes/admin/views/UserDetail.jsx

@@ -1,4 +1,4 @@
-import { useMemo } from 'react'
+import { useCallback, useEffect, useMemo, useState } from 'react'
 import { useParams, Link } from 'react-router-dom'
 import { Loading, ErrorState } from '../../../components/PageState.jsx'
 import { useAsync } from '../../../lib/useAsync.js'
@@ -136,6 +136,114 @@ function Houses({ scope }) {
   )
 }
 
+// Admin security controls for one user: their trusted devices (view + revoke) and
+// an MFA reset for a locked-out user. Every action is audit-logged server-side.
+function SecurityAdmin({ userId }) {
+  const [devices, setDevices] = useState(null)
+  const [error, setError] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [msg, setMsg] = useState('')
+
+  const load = useCallback(async () => {
+    try {
+      setDevices(await api.admin.userTrustedDevices(userId))
+    } catch {
+      setError('Could not load trusted devices.')
+    }
+  }, [userId])
+  useEffect(() => {
+    load()
+  }, [load])
+
+  async function revoke(deviceId) {
+    setBusy(true); setMsg(''); setError('')
+    try {
+      await api.admin.revokeUserTrustedDevice(userId, deviceId)
+      await load()
+    } catch {
+      setError('Could not revoke that device.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  async function revokeAll() {
+    if (!window.confirm('Revoke ALL of this user’s trusted devices?')) return
+    setBusy(true); setMsg(''); setError('')
+    try {
+      await api.admin.revokeAllUserTrustedDevices(userId)
+      setMsg('All trusted devices revoked.')
+      await load()
+    } catch {
+      setError('Could not revoke devices.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  async function resetMfa() {
+    if (!window.confirm('Reset this user’s two-factor? This turns TOTP off, revokes their trusted devices, and clears their recovery codes so they can sign in with their password.')) return
+    setBusy(true); setMsg(''); setError('')
+    try {
+      await api.admin.resetUserMfa(userId)
+      setMsg('Two-factor has been reset for this user.')
+      await load()
+    } catch {
+      setError('Could not reset two-factor.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  const fmt = (d) => {
+    const t = d ? new Date(d) : null
+    return t && !Number.isNaN(t.getTime()) ? t.toLocaleDateString() : '—'
+  }
+
+  return (
+    <section style={{ borderTop: '1px solid var(--line-soft)', marginTop: 30, paddingTop: 22 }}>
+      <SectionTitle>Security &amp; two-factor</SectionTitle>
+      {devices == null ? (
+        <p className="sans dim" style={{ margin: 0, fontSize: '0.86rem' }}>Loading…</p>
+      ) : devices.length === 0 ? (
+        <p className="sans dim" style={{ margin: 0, fontSize: '0.86rem' }}>No trusted devices.</p>
+      ) : (
+        <ul style={{ listStyle: 'none', margin: '0 0 14px', padding: 0, display: 'flex', flexDirection: 'column', gap: 8 }}>
+          {devices.map((d) => (
+            <li key={d.id} style={{ display: 'flex', alignItems: 'center', gap: 12, padding: '10px 14px', border: '1px solid var(--line)', borderRadius: 8 }}>
+              <div style={{ flex: 1, minWidth: 0 }}>
+                <div className="sans" style={{ color: 'var(--head)', fontSize: '0.9rem' }}>
+                  {d.deviceName || (d.platform === 'mobile' ? 'Mobile app' : 'Browser')}
+                </div>
+                <div className="sans dim" style={{ fontSize: '0.76rem', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
+                  {d.userAgent || '—'} · last used {fmt(d.lastUsedAt)} · expires {fmt(d.expiresAt)}
+                </div>
+              </div>
+              <button onClick={() => revoke(d.id)} disabled={busy} className="pill" style={{ color: '#d98b84', borderColor: '#d98b84' }}>
+                Revoke
+              </button>
+            </li>
+          ))}
+        </ul>
+      )}
+
+      <div style={{ display: 'flex', gap: 10, alignItems: 'center', flexWrap: 'wrap' }}>
+        {devices && devices.length > 0 && (
+          <button onClick={revokeAll} disabled={busy} className="pill" style={{ color: '#d98b84', borderColor: '#d98b84' }}>
+            Revoke all trusted devices
+          </button>
+        )}
+        <button onClick={resetMfa} disabled={busy} className="btn btn-sq" style={{ borderColor: '#d98b84', color: '#d98b84' }}>
+          Reset two-factor
+        </button>
+      </div>
+
+      {msg && <p className="sans" style={{ marginTop: 12, color: '#7fd0a4', fontSize: '0.86rem' }}>{msg}</p>}
+      {error && <p className="sans" style={{ marginTop: 12, color: '#d98b84', fontSize: '0.86rem' }}>{error}</p>}
+    </section>
+  )
+}
+
 function ShardSections({ scope }) {
   return (
     <>
@@ -187,6 +295,7 @@ export default function UserDetail() {
         </div>
       </div>
 
+      <SecurityAdmin userId={id} />
       <ShardSections scope={scope} />
     </section>
   )