feat(moderation): appeals (6c) + Discord reversal on approve (6d)

Players whose linked Discord identity was banned or muted can now submit
an appeal from the portal and track it; staff get a queue in the admin
moderation section to claim and resolve (approve/deny) appeals. Approving
a ban/mute appeal best-effort asks the Discord bot to reverse the action
(unban / clear timeout) via the internal API and posts a mod-log embed; a
down bot never fails the resolution (reversal_status is recorded).

- Schema: new server-owned `appeals` table (no cross-owner FK to
  mod_actions; existence validated in app code).
- Server: model/appeals/* + player appeals controller (submit/mine/
  eligible/withdraw) and admin queue handlers (list/claim/resolve/
  per-user) under the existing admin+moderator gate; one-active-appeal
  enforced app-side; eligibility keyed on the caller's linked Discord id.
- 6d: bot POST /internal/mod-reverse (+ modLog.postReversal) and
  server botInternalClient.reverseModAction, wired into resolve().
- Client: admin Appeals queue + resolve modal, ModerationUser appeals
  tab, player Appeals page (submit/withdraw), nav + routes + api methods.
- Docs: swagger annotations + component schemas, regenerated output.
- Tests: appeals controller + pure suites (server npm test 224 green).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XmHdsbnLzDMAVQkAoTQSBe

client/src/routes/admin/AdminLayout.jsx

@@ -63,6 +63,7 @@ const NAV = [
     title: 'Moderation',
     items: [
       { to: '/admin/moderation', label: 'Moderation', icon: IconShield, roles: ['admin', 'moderator'] },
+      { to: '/admin/moderation/appeals', label: 'Appeals', icon: IconShield, roles: ['admin', 'moderator'] },
       { to: '/admin/shard-ops', label: 'In-Game Ops', icon: IconShard, roles: ['admin', 'moderator'] },
       { to: '/admin/houses', label: 'Houses', icon: IconShard, roles: ['admin', 'moderator'] },
     ],
@@ -97,6 +98,7 @@ const TITLES = {
   '/admin/wiki': 'Wiki Pages',
   '/admin/hero': 'Hero Editor',
   '/admin/moderation': 'Moderation',
+  '/admin/moderation/appeals': 'Appeals',
   '/admin/shard-ops': 'In-Game Ops',
   '/admin/houses': 'House Registry',
   '/admin/settings': 'Site Settings',
@@ -145,7 +147,7 @@ export default function AdminLayout() {
   // Moderators only get the moderation section (Discord + in-game ops) + their
   // own account security.
   const isModerator = user?.role === 'moderator'
-  const MOD_PATHS = ['/admin/moderation', '/admin/shard-ops', '/admin/houses', '/admin/account']
+  const MOD_PATHS = ['/admin/moderation', '/admin/moderation/appeals', '/admin/shard-ops', '/admin/houses', '/admin/account']
   const visible = (item) => {
     if (item.roles && !item.roles.includes(user?.role)) return false
     if (isModerator) return MOD_PATHS.includes(item.to)