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/components/security/TrustedDevicesPanel.jsx

@@ -0,0 +1,137 @@
+import { useCallback, useEffect, useState } from 'react'
+import { api } from '../../api/client.js'
+import TrustLimitModal from './TrustLimitModal.jsx'
+
+// Self-service list of the devices allowed to skip the TOTP step at login (MFA
+// "Trust this device"). Uses the role-agnostic /auth/me/trusted-devices surface, so
+// the same panel serves players and staff. Shown only when 2FA is enabled — trust
+// is meaningless without a second factor to skip.
+function fmtDate(s) {
+  if (!s) return '—'
+  const d = new Date(s)
+  return Number.isNaN(d.getTime()) ? '—' : d.toLocaleDateString(undefined, { year: 'numeric', month: 'short', day: 'numeric' })
+}
+
+export default function TrustedDevicesPanel() {
+  const [devices, setDevices] = useState(null)
+  const [error, setError] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [msg, setMsg] = useState('')
+  const [capModal, setCapModal] = useState(null) // { devices } when the cap is hit
+
+  const load = useCallback(async () => {
+    try {
+      setDevices(await api.myTrustedDevices())
+    } catch {
+      setError('Could not load your trusted devices.')
+    }
+  }, [])
+  useEffect(() => {
+    load()
+  }, [load])
+
+  async function trustThis() {
+    setBusy(true)
+    setMsg('')
+    setError('')
+    try {
+      await api.trustThisDevice()
+      setMsg('This device is now trusted.')
+      await load()
+    } catch (err) {
+      if (err.status === 409 && err.body?.error === 'trusted_device_limit') {
+        setCapModal({ devices: err.body.devices || [] })
+      } else {
+        setError('Could not trust this device.')
+      }
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  async function revoke(id) {
+    setBusy(true)
+    setMsg('')
+    setError('')
+    try {
+      await api.revokeTrustedDevice(id)
+      await load()
+    } catch {
+      setError('Could not revoke that device.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  async function revokeAll() {
+    if (!window.confirm('Untrust every device? Each will require the full two-factor step at the next login.')) return
+    setBusy(true)
+    setMsg('')
+    setError('')
+    try {
+      await api.revokeAllTrustedDevices()
+      setMsg('All devices untrusted.')
+      await load()
+    } catch {
+      setError('Could not untrust devices.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  if (!devices) return null
+
+  return (
+    <div style={{ marginTop: 40, borderTop: '1px solid var(--line-soft)', paddingTop: 28 }}>
+      <h2 className="display" style={{ marginTop: 0, fontSize: '1.2rem', color: 'var(--head)' }}>
+        Trusted devices
+      </h2>
+      <p className="sans" style={{ color: 'var(--muted)', fontSize: '0.9rem', lineHeight: 1.6 }}>
+        Devices you’ve trusted skip the authenticator step at login (your password is still required).
+        Revoke any you don’t recognize.
+      </p>
+
+      {devices.length > 0 ? (
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 10, margin: '14px 0' }}>
+          {devices.map((d) => (
+            <div 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 {fmtDate(d.lastUsedAt)} · expires {fmtDate(d.expiresAt)}
+                </div>
+              </div>
+              <button onClick={() => revoke(d.id)} disabled={busy} className="pill" style={{ color: '#d98b84', borderColor: '#d98b84' }}>
+                Revoke
+              </button>
+            </div>
+          ))}
+        </div>
+      ) : (
+        <p className="sans dim" style={{ fontSize: '0.86rem', margin: '14px 0' }}>No trusted devices yet.</p>
+      )}
+
+      <div style={{ display: 'flex', gap: 10, alignItems: 'center', flexWrap: 'wrap' }}>
+        <button onClick={trustThis} disabled={busy} className="btn btn-sq">Trust this device</button>
+        {devices.length > 0 && (
+          <button onClick={revokeAll} disabled={busy} className="pill" style={{ color: '#d98b84', borderColor: '#d98b84' }}>
+            Untrust all
+          </button>
+        )}
+      </div>
+
+      {msg && <p className="sans" style={{ marginTop: 14, color: '#7fd0a4', fontSize: '0.86rem' }}>{msg}</p>}
+      {error && <p className="sans" style={{ marginTop: 14, color: '#d98b84', fontSize: '0.86rem' }}>{error}</p>}
+
+      {capModal && (
+        <TrustLimitModal
+          devices={capModal.devices}
+          onTrusted={() => { setCapModal(null); setMsg('This device is now trusted.'); load() }}
+          onCancel={() => setCapModal(null)}
+        />
+      )}
+    </div>
+  )
+}