add setup wizard, lockdown, team tasks, embed builder; fix admin dashboard

Four new independent features: /setup (guided onboarding wizard for
module/channel/automod-strength config), /lockdown (raid protection with
per-channel permission snapshot/restore and join-kick), /task (staff task
tracker with status buttons + dashboard view), /embed create (modal-driven
embed builder with optional link button). Also fixes the Admin dashboard,
which always showed "-" because loadAdminData() double-wrapped the overview
response and discarded activity data, plus mismatched field names against
adminService's actual shape (guildCount/activeGuilds24/uptimeMs).

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

src/events/guildMemberAdd.ts

@@ -6,6 +6,11 @@ import { settingsStore } from '../config/state';
 const event: EventHandler = {
   name: 'guildMemberAdd',
   execute(member: GuildMember) {
+    if (context.lockdown.isActive(member.guild.id)) {
+      member.kick('Lockdown aktiv - neue Mitglieder werden abgewiesen').catch(() => undefined);
+      context.logging.logMemberJoin(member);
+      return;
+    }
     const guildConfig = settingsStore.get(member.guild.id);
     const welcomeCfg = guildConfig?.welcomeConfig || guildConfig?.automodConfig?.welcomeConfig;
     if (welcomeCfg?.enabled && welcomeCfg.channelId) {