fix: update TalkService for Talk 14 compatibility and add CLI copy helper

- **TalkService**:
  - Refactored `ensureBotParticipants` to use `AttendeeMapper` directly, removing the dependency on `ParticipantService`.
  - Added `getBotDisplayNameForRoom` to resolve the bot's display name via direct DB query.
  - Updated `sendMessage` to use Chat API v1 and include `richObjectsEnd`.
  - Improved `getBaseUrl` logic to handle `overwritehost` and `overwritewebroot`.
- **WebhookController**:
  - Fixed `getAllValues` to iterate known keys manually, preventing `RuntimeException` in Nextcloud 33.
  - Added error handling for `saveConfig`.
  - Removed unused `ParticipantService` import.
- **js/settings.js**:
  - Added functionality to copy CLI commands to the clipboard.
- **Deletions**:
  - Removed `lib/Command/AddBotParticipant.php` as its logic is now integrated into `TalkService`.
- **Templates**:
  - Updated admin settings labels and comments.

lib/Settings/Admin.php

@@ -28,6 +28,7 @@ class Admin implements ISettings {
             'configuredRooms' => $this->talkService->getRooms(),
             'serverUrl' => $this->talkService->getBaseUrl(),
             'senderName' => $this->talkService->getSenderNameDefault(),
+            // CLI commands for setup (user copies these to their server)
             'l10n' => [
                 'fetch_rooms' => $this->l10n->t('Fetch Rooms'),
                 'error_fetching' => $this->l10n->t('Error fetching rooms'),