Add Discord bot (moderation, filters, scheduling, roles, invites, site integration)

Standalone bot/ service (its own package.json/Dockerfile) managed entirely
through a new admin-only Discord Bot panel — token stored encrypted in the
DB and pushed to the bot process in-memory, never an env var. Built in
phases, each independently verified against a live Discord guild:

- Bot skeleton: gateway connection, internal shared-secret API, self-heals
  on its own restart by pulling config from the site
- Moderation core: /ban /kick /mute /warn /warnings + mod-log channel
- Word/invite/spam filtering with leetspeak-resistant normalization and a
  staff role/channel allowlist
- Scheduled messages: recurring (cron) and one-off channel posts
- Role assignment: button role menus, auto-role on join, temp roles,
  bulk role ops
- Auto-rotating primary invite with an audit log
- Site integration: news-publish -> Discord announce webhook, manual
  /announce, read-only /wiki search

Also fixes a pre-existing bug in both DB pools (server + bot): the mariadb
driver defaulted to timezone 'local', silently mis-serializing bound Date
params by the host's local offset instead of the DB's UTC session.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

client/src/App.jsx

@@ -27,6 +27,7 @@ import HeroEditor from './routes/admin/views/HeroEditor.jsx'
 import SettingsAdmin from './routes/admin/views/SettingsAdmin.jsx'
 import ActivityAdmin from './routes/admin/views/ActivityAdmin.jsx'
 import BotActivityAdmin from './routes/admin/views/BotActivityAdmin.jsx'
+import DiscordBotAdmin from './routes/admin/views/DiscordBotAdmin.jsx'
 import AuthProvidersAdmin from './routes/admin/views/AuthProvidersAdmin.jsx'
 import UsersAdmin from './routes/admin/views/UsersAdmin.jsx'
 import AccountAdmin from './routes/admin/views/AccountAdmin.jsx'
@@ -74,6 +75,7 @@ export default function App() {
             <Route path="settings" element={<SettingsAdmin />} />
             <Route path="activity" element={<ActivityAdmin />} />
             <Route path="bot-activity" element={<BotActivityAdmin />} />
+            <Route path="discord-bot" element={<DiscordBotAdmin />} />
             <Route path="auth-providers" element={<AuthProvidersAdmin />} />
             <Route path="users" element={<UsersAdmin />} />
             <Route path="account" element={<AccountAdmin />} />