feat(account): self-service account deletion, MODULE_API 1.20.0

ACCOUNT_DELETION.md phase 2 (core): a member deletes their own account on
the website, and the admin route runs the same procedure.

- DELETE /api/v1/auth/me/account: typed username, password always (AD7),
  and a 2FA or recovery code when 2FA is on. A wrong password or code is
  400, not 401 (AD12), so the app's refresh-on-401 never replays it.
  409 password_required and last_admin; the demo's shared logins are
  locked.
- auth/accountDeletion.js: module hooks first, then one transaction that
  reserves a staff username (reserved_usernames, AD9) and deletes the row,
  then a Teams reconcile, the audit entry (no username) and a notice to
  the old address (new protected template auth.account-deleted).
- MODULE_API 1.20.0: api.onUserDeleting({ userId, deletedBy }), before the
  delete, 10 s limit, cannot veto (AD10, AD11).
- utils/displayAuthor.js: a deleted account's username snapshots read
  "[deleted player]" to members and the stored name, marked, to staff
  (AD5, AD6). Used by the forum, the Reports queue, the guest list and
  the Team digest. A deleted account drops off Forum guests (AD13).
- Reserved names refuse at every username write, answered as "taken".
- Web: Delete my account on the player and staff Account pages; staff
  views mark "(deleted account)".
- OpenAPI regenerated; route manifest and engagement manifest regenerated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

client/src/routes/admin/views/TeamsAdmin.jsx

@@ -1,6 +1,7 @@
 import { useCallback, useEffect, useState } from 'react'
 import { Loading, ErrorState } from '../../../components/PageState.jsx'
 import { dateTime } from '../../../lib/format.js'
+import { rowName } from '../../../lib/deletedAccount.js'
 import {
   freshnessOf, statusOf, gateLabelFor, describeRequest, leadershipOf, GATED_NOTE,
 } from '../../../lib/teamAdmin.js'
@@ -331,7 +332,7 @@ function ForumLedger({ team, onClose }) {
                   <td className="adm-td dim">{dateTime(r.created_at)}</td>
                   <td className="adm-td" style={{ color: 'var(--head)' }}>{r.action}</td>
                   <td className="adm-td dim">{r.target_type} #{r.target_id}</td>
-                  <td className="adm-td">{r.actor_username || '—'}</td>
+                  <td className="adm-td">{rowName(r.actor_user_id, r.actor_username)}</td>
                   <td className="adm-td">
                     {/* The distinction the whole ledger exists to preserve. */}
                     <Pill tone={r.actor_role === 'staff' ? 'warn' : 'ok'}>{r.actor_role}</Pill>