feat: UX & notification improvements — icons, events, chat names, link validation, templates

- Show entity icons on all cards with fallback defaults (providers, trackers, targets, bots)
- Enrich EventLog with provider_name, tracker_name, assets_count; add DB migration
- Dashboard events: filtering (type, provider, search), sorting, pagination, dynamic page size
- Friendly chat names on telegram target cards (resolve from TelegramChat table)
- Test message button on bot chat items with locale-aware messages
- Album public link validation on tracker save with auto-create dialog
- Support albums without public links: conditional <a href> in templates
- Fetch shared links during poll, enrich events with public_url/protected_url
- Per-asset public_url in template context ({share_url}/photos/{asset_id})
- Common date/location detection: common_date + common_location context vars
- Dual date formats: date_format (datetime) + date_only_format (date only)
- Template clone button, HTML link rendering in template preview
- Fix Telegram asset download 401: pass x-api-key headers through client
- Fix provider external_url matching for API key scoping
- Fix event timestamp timezone (append Z suffix for UTC)
- Localize event filter controls, test messages (EN/RU)
- Template variable UI helpers updated with all new fields
- CLAUDE.md: template system sync rules documentation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/lib/i18n/ru.json

@@ -46,7 +46,20 @@
 		"assetsRemoved": "удалены файлы",
 		"collectionRenamed": "альбом переименован",
 		"collectionDeleted": "альбом удалён",
-		"sharingChanged": "изменение доступа"
+		"sharingChanged": "изменение доступа",
+		"searchEvents": "Поиск событий...",
+		"allEvents": "Все события",
+		"filterAssetsAdded": "Добавление файлов",
+		"filterAssetsRemoved": "Удаление файлов",
+		"filterRenamed": "Переименование",
+		"filterDeleted": "Удаление",
+		"filterSharingChanged": "Изменение доступа",
+		"allProviders": "Все провайдеры",
+		"newestFirst": "Сначала новые",
+		"oldestFirst": "Сначала старые",
+		"loadingEvents": "Загрузка событий...",
+		"asset": "файл",
+		"assets": "файлов"
 	},
 	"providers": {
 		"title": "Провайдеры",
@@ -284,7 +297,8 @@
 		"moreMessage": "Сообщение \"ещё\"",
 		"peopleFormat": "Формат людей",
 		"dateLocation": "Дата и место",
-		"dateFormat": "Формат даты",
+		"dateFormat": "Формат даты и времени",
+		"dateOnlyFormat": "Формат даты",
 		"commonDate": "Общая дата",
 		"uniqueDate": "Дата файла",
 		"locationFormat": "Формат места",
@@ -417,6 +431,7 @@
 		"save": "Сохранить",
 		"cancel": "Отмена",
 		"delete": "Удалить",
+		"clone": "Копировать",
 		"edit": "Редактировать",
 		"description": "Описание",
 		"close": "Закрыть",