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

server/src/utils/botInternalClient.js

@@ -61,4 +61,15 @@ function announce({ title, excerpt, url, imageUrl }) {
   return call('/internal/announce', { method: 'POST', body: { title, excerpt, url, imageUrl } })
 }
 
-module.exports = { pushConfig, getStatus, announce }
+// Site -> bot: an approved appeal wants the underlying Discord action reversed
+// (unban for a 'ban', clear the timeout for a 'mute'). Best-effort like every
+// call here — never throws, so an approved appeal still resolves when the bot is
+// down (the caller records reversal_status='failed' from `ok:false`).
+function reverseModAction({ discordUserId, actionType, appealId }) {
+  return call('/internal/mod-reverse', {
+    method: 'POST',
+    body: { discord_user_id: discordUserId, action_type: actionType, appeal_id: appealId },
+  })
+}
+
+module.exports = { pushConfig, getStatus, announce, reverseModAction }