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/messages/en.json

@@ -668,29 +668,36 @@
     },
     "tickets": {
       "title": "Tickets",
-      "description": "Configure how support tickets are created and managed.",
+      "description": "Configure how support tickets are created. Saving (enabled, with panel channel and at least one category) posts or updates the ticket panel in the selected channel.",
       "enabledLabel": "Tickets module enabled",
       "mode": "Ticket mode",
       "modes": {
         "CHANNEL": "Private channel",
         "THREAD": "Private thread"
       },
-      "categoryId": "Ticket category ID",
+      "panelChannelId": "Panel channel",
+      "panelChannelHint": "Channel where the ticket panel with category buttons is posted.",
+      "categoryId": "Discord category for ticket channels",
       "logChannelId": "Log channel",
       "inactivityHours": "Auto-close after inactivity (hours)",
       "transcriptDm": "DM transcript to ticket creator",
       "transcriptDmHint": "Sends a transcript to the user via DM once their ticket is closed.",
       "ratingEnabled": "Ask for a rating after closing",
       "categoriesTitle": "Ticket categories",
-      "categoriesDescription": "Categories members can choose from when opening a ticket.",
+      "categoriesDescription": "Categories members can choose from when opening a ticket. Changes update an existing panel.",
       "categoriesEmpty": "No ticket categories configured yet.",
       "categoryName": "Name",
       "categoryEmoji": "Emoji",
       "categoryDescription": "Description",
-      "supportRoleIds": "Support role IDs",
+      "supportRoleIds": "Support roles",
       "idsPlaceholder": "One or more IDs, comma-separated",
       "addCategory": "Add category",
-      "nameRequired": "A name is required."
+      "nameRequired": "A name is required.",
+      "errors": {
+        "panelTimeout": "The bot did not confirm the ticket panel in time. It may still be posting — check the channel and bot permissions, then save again.",
+        "panelNotPosted": "The ticket panel could not be created in the Discord channel. Check bot permissions (View Channel, Send Messages, Embed Links).",
+        "noCategories": "Create at least one ticket category before the panel can be posted."
+      }
     },
     "giveaways": {
       "formIncomplete": "Please fill in the channel, prize and end date.",