Implement ticket panel synchronization and configuration updates

- Added `panelChannelId` and `panelMessageId` fields to the `TicketConfig` model for managing ticket panel settings.
- Introduced `syncTicketPanel` function to handle posting and updating the ticket panel in Discord channels via BullMQ.
- Enhanced error handling for ticket panel synchronization, including specific error messages for missing categories and posting failures.
- Updated WebUI components to support panel channel selection and improved error messaging for synchronization issues.
- Added localization entries for new error messages related to ticket panel synchronization in both English and German.
- Refactored ticket category management to trigger panel synchronization upon category creation, update, or deletion.

apps/webui/src/app/api/guilds/[guildId]/tickets/route.ts

@@ -2,7 +2,11 @@ import { TicketConfigDashboardPatchSchema } from '@nexumi/shared';
 import { type NextRequest, NextResponse } from 'next/server';
 import { requireGuildAccess, toApiErrorResponse } from '@/lib/auth';
 import { writeDashboardAudit } from '@/lib/audit';
-import { getTicketConfigDashboard, updateTicketConfigDashboard } from '@/lib/module-configs/tickets';
+import {
+  getTicketConfigDashboard,
+  TicketPanelSyncError,
+  updateTicketConfigDashboard
+} from '@/lib/module-configs/tickets';
 import { prisma } from '@/lib/prisma';
 
 interface RouteParams {
@@ -41,6 +45,12 @@ export async function PATCH(request: NextRequest, { params }: RouteParams) {
 
     return NextResponse.json(after);
   } catch (error) {
+    if (error instanceof TicketPanelSyncError) {
+      return NextResponse.json(
+        { error: error.message, code: error.code },
+        { status: error.code === 'timeout' ? 504 : 502 }
+      );
+    }
     return toApiErrorResponse(error);
   }
 }