feat: collapsible chart, paginator controls, localized template slots

- Dashboard chart collapsible with state persisted in localStorage
- Events per page user-controlled (5/10/20/50) via select, persisted
- Paginator rendered both above and below event list (shared snippet)
- Removed viewport-based page size calculation
- Template slot descriptions localized (templateSlot.* i18n keys)
- Preview As target selector expanded: email, discord, slack added
- Tighter event item spacing

frontend/src/lib/grid-items.ts

@@ -105,8 +105,11 @@ export const chatActionItems = (): GridItem[] => [
 // --- Preview target type ---
 
 export const previewTargetTypeItems = (): GridItem[] => [
-	{ value: 'telegram', icon: 'mdiSend', label: t('targets.typeTelegram'), desc: t('gridDesc.previewTelegram') },
-	{ value: 'webhook', icon: 'mdiWebhook', label: t('targets.typeWebhook'), desc: t('gridDesc.previewWebhook') },
+	{ value: 'telegram', icon: 'mdiSend', label: 'Telegram', desc: t('gridDesc.previewTelegram') },
+	{ value: 'webhook', icon: 'mdiWebhook', label: 'Webhook', desc: t('gridDesc.previewWebhook') },
+	{ value: 'email', icon: 'mdiEmailOutline', label: 'Email', desc: t('gridDesc.previewEmail') },
+	{ value: 'discord', icon: 'mdiChat', label: 'Discord', desc: t('gridDesc.previewDiscord') },
+	{ value: 'slack', icon: 'mdiSlack', label: 'Slack', desc: t('gridDesc.previewSlack') },
 ];
 
 // --- Provider type items (derived from descriptor registry) ---

frontend/src/lib/i18n/en.json

@@ -60,6 +60,7 @@
 		"activeTrackers": "Active Trackers",
 		"targets": "Targets",
 		"recentEvents": "Events",
+		"chart": "Event chart",
 		"noEvents": "No events yet. Create a tracker to start monitoring.",
 		"loading": "Loading...",
 		"justNow": "just now",
@@ -837,6 +838,49 @@
 		"noFilterResults": "No items match the current filter.",
 		"redirecting": "Redirecting..."
 	},
+	"templateSlot": {
+		"message_assets_added": "New assets added to album",
+		"message_assets_removed": "Assets removed from album",
+		"message_collection_renamed": "Album renamed",
+		"message_collection_deleted": "Album deleted",
+		"message_sharing_changed": "Sharing status changed",
+		"periodic_summary_message": "Periodic album summary",
+		"scheduled_assets_message": "Scheduled asset delivery",
+		"memory_mode_message": "On This Day memories",
+		"message_push": "Code pushed to repository",
+		"message_issue_opened": "Issue opened",
+		"message_issue_closed": "Issue closed",
+		"message_issue_commented": "Comment on issue",
+		"message_pr_opened": "Pull request opened",
+		"message_pr_closed": "Pull request closed",
+		"message_pr_merged": "Pull request merged",
+		"message_pr_commented": "Comment on pull request",
+		"message_release_published": "Release published",
+		"message_scheduled_message": "Scheduled message",
+		"message_card_created": "Card created",
+		"message_card_updated": "Card updated",
+		"message_card_moved": "Card moved between lists",
+		"message_card_deleted": "Card deleted",
+		"message_card_commented": "Comment added to card",
+		"message_comment_updated": "Comment updated",
+		"message_board_created": "Board created",
+		"message_board_updated": "Board updated",
+		"message_board_deleted": "Board deleted",
+		"message_list_created": "List created",
+		"message_list_updated": "List updated",
+		"message_list_deleted": "List deleted",
+		"message_attachment_created": "Attachment added to card",
+		"message_card_label_added": "Label added to card",
+		"message_task_completed": "Task completed",
+		"message_ups_online": "UPS back on mains power",
+		"message_ups_on_battery": "UPS switched to battery",
+		"message_ups_low_battery": "Battery critically low",
+		"message_ups_battery_restored": "Battery charge recovered",
+		"message_ups_comms_lost": "Communication with UPS lost",
+		"message_ups_comms_restored": "Communication with UPS restored",
+		"message_ups_replace_battery": "Battery needs replacement",
+		"message_ups_overload": "UPS load exceeded capacity"
+	},
 	"gridDesc": {
 		"sortNone": "No sorting applied",
 		"sortDate": "Sort by creation date",
@@ -874,6 +918,9 @@
 		"chatActionRecordVoice": "Show recording voice...",
 		"previewTelegram": "Preview with Telegram HTML format",
 		"previewWebhook": "Preview as plain text",
+		"previewEmail": "Preview with email HTML format",
+		"previewDiscord": "Preview with Discord markdown",
+		"previewSlack": "Preview with Slack markdown",
 		"providerImmich": "Self-hosted photo server",
 		"providerGitea": "Self-hosted Git service",
 		"providerPlanka": "Self-hosted Kanban board",

frontend/src/lib/i18n/ru.json

@@ -60,6 +60,7 @@
 		"activeTrackers": "Активные трекеры",
 		"targets": "Получатели",
 		"recentEvents": "События",
+		"chart": "График событий",
 		"noEvents": "Событий пока нет. Создайте трекер для отслеживания.",
 		"loading": "Загрузка...",
 		"justNow": "только что",
@@ -837,6 +838,49 @@
 		"noFilterResults": "Нет элементов, соответствующих фильтру.",
 		"redirecting": "Перенаправление..."
 	},
+	"templateSlot": {
+		"message_assets_added": "Новые файлы добавлены в альбом",
+		"message_assets_removed": "Файлы удалены из альбома",
+		"message_collection_renamed": "Альбом переименован",
+		"message_collection_deleted": "Альбом удалён",
+		"message_sharing_changed": "Статус общего доступа изменён",
+		"periodic_summary_message": "Периодическая сводка альбома",
+		"scheduled_assets_message": "Запланированная отправка файлов",
+		"memory_mode_message": "Воспоминания «В этот день»",
+		"message_push": "Код отправлен в репозиторий",
+		"message_issue_opened": "Issue открыт",
+		"message_issue_closed": "Issue закрыт",
+		"message_issue_commented": "Комментарий к issue",
+		"message_pr_opened": "Pull request открыт",
+		"message_pr_closed": "Pull request закрыт",
+		"message_pr_merged": "Pull request слит",
+		"message_pr_commented": "Комментарий к pull request",
+		"message_release_published": "Релиз опубликован",
+		"message_scheduled_message": "Запланированное сообщение",
+		"message_card_created": "Карточка создана",
+		"message_card_updated": "Карточка обновлена",
+		"message_card_moved": "Карточка перемещена",
+		"message_card_deleted": "Карточка удалена",
+		"message_card_commented": "Комментарий к карточке",
+		"message_comment_updated": "Комментарий обновлён",
+		"message_board_created": "Доска создана",
+		"message_board_updated": "Доска обновлена",
+		"message_board_deleted": "Доска удалена",
+		"message_list_created": "Список создан",
+		"message_list_updated": "Список обновлён",
+		"message_list_deleted": "Список удалён",
+		"message_attachment_created": "Вложение добавлено",
+		"message_card_label_added": "Метка добавлена к карточке",
+		"message_task_completed": "Задача выполнена",
+		"message_ups_online": "ИБП на сетевом питании",
+		"message_ups_on_battery": "ИБП перешёл на батарею",
+		"message_ups_low_battery": "Батарея критически разряжена",
+		"message_ups_battery_restored": "Заряд батареи восстановлен",
+		"message_ups_comms_lost": "Связь с ИБП потеряна",
+		"message_ups_comms_restored": "Связь с ИБП восстановлена",
+		"message_ups_replace_battery": "Батарея требует замены",
+		"message_ups_overload": "ИБП перегружен"
+	},
 	"gridDesc": {
 		"sortNone": "Без сортировки",
 		"sortDate": "По дате создания",
@@ -874,6 +918,9 @@
 		"chatActionRecordVoice": "Показать «записывает голос...»",
 		"previewTelegram": "Предпросмотр в формате Telegram HTML",
 		"previewWebhook": "Предпросмотр как текст",
+		"previewEmail": "Предпросмотр в формате Email HTML",
+		"previewDiscord": "Предпросмотр в формате Discord",
+		"previewSlack": "Предпросмотр в формате Slack",
 		"providerImmich": "Фотосервер для самостоятельного размещения",
 		"providerGitea": "Git-сервер для самостоятельного размещения",
 		"providerPlanka": "Канбан-доска для самостоятельного размещения",