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/model/appeals/appeals.model.js

@@ -0,0 +1,82 @@
+// Business layer for moderation appeals (Phase 6c). A thin wrapper over
+// appeals.db that returns the freshly-read row after each mutation, so callers
+// always hand the client the enriched (joined) shape rather than a bare
+// insert/update result. Ownership/type/duplicate validation lives in the
+// controllers (they hold the request context — caller identity, the mod_action
+// being appealed); this layer just performs the persistence.
+const appealsDb = require('./appeals.db')
+
+async function submit({ modActionId, discordUserId, actionType, userId, submittedText }) {
+  const id = await appealsDb.insert({ modActionId, discordUserId, actionType, userId, submittedText })
+  return appealsDb.getById(id)
+}
+
+async function getById(id) {
+  return appealsDb.getById(id)
+}
+
+// The caller's own appeals, newest first.
+async function listMine(userId) {
+  return appealsDb.listForUser(userId)
+}
+
+// The caller's appealable actions (ban/mute with no active appeal).
+async function eligibleActions(discordUserId) {
+  return appealsDb.eligibleActions(discordUserId)
+}
+
+// The active (pending/under_review) appeal for an action, or null.
+async function activeForAction(modActionId) {
+  return appealsDb.activeForAction(modActionId)
+}
+
+// Owner-initiated withdraw: flip to 'withdrawn' and return the updated row.
+async function withdraw(id) {
+  await appealsDb.setStatus(id, 'withdrawn')
+  return appealsDb.getById(id)
+}
+
+// Staff queue read.
+async function queue({ statuses, limit, offset }) {
+  return appealsDb.listQueue({ statuses, limit, offset })
+}
+
+// Staff claim: pending -> under_review, stamping the handler.
+async function claim(id, { handlerUserId, handlerTag }) {
+  await appealsDb.setUnderReview(id, { handlerUserId, handlerTag })
+  return appealsDb.getById(id)
+}
+
+// Staff resolution (approved/denied) with the reversal outcome already decided
+// by the controller (which owns the best-effort bot call).
+async function resolve(id, opts) {
+  await appealsDb.resolve(id, opts)
+  return appealsDb.getById(id)
+}
+
+// Appeals for a Discord id (admin per-user view).
+async function listForDiscordUser(discordUserId) {
+  return appealsDb.listForDiscordUser(discordUserId)
+}
+
+// Number of appeals still awaiting first triage (status = 'pending'), for the
+// dashboard badge.
+async function pendingCount() {
+  const rows = await appealsDb.countByStatus()
+  const row = rows.find((r) => r.status === 'pending')
+  return row ? Number(row.c) : 0
+}
+
+module.exports = {
+  submit,
+  getById,
+  listMine,
+  eligibleActions,
+  activeForAction,
+  withdraw,
+  queue,
+  claim,
+  resolve,
+  listForDiscordUser,
+  pendingCount,
+}