Refactor AI summarizer client initialization to include MongoDB manager and add statistics endpoint

- Updated `InitAISummarizerClient` to accept `mongoManager` for tracking translation success.
- Introduced new `Statistics` endpoint in the dashboard to fetch scraping and translation statistics.
- Enhanced `TranslationWorker` to utilize the new success counter for tracking successful translations.
- Added necessary data structures and query forms for statistics reporting.

This refactor improves the tracking of AI translation success and provides new insights through the dashboard statistics.

internal/dashboard/repository.go

@@ -23,18 +23,23 @@ type Repository interface {
 	NoticeTypes(ctx context.Context) (*NoticeTypesResponse, error)
 	ClosingSoon(ctx context.Context, limit int, windowSec int64) ([]ClosingSoonItem, error)
 	Recent(ctx context.Context, limit int, cursor string) ([]RecentItem, *string, error)
+	Statistics(ctx context.Context, days int, startUnix int64) (*StatisticsReportResponse, error)
 }
 
 type repository struct {
-	ormRepo orm.Repository[tender.Tender]
-	logger  logger.Logger
+	ormRepo        orm.Repository[tender.Tender]
+	mongoManager   *orm.ConnectionManager
+	metricsCounter *orm.Counter
+	logger         logger.Logger
 }
 
 // NewRepository creates a dashboard repository backed by the tenders collection.
 func NewRepository(mongoManager *orm.ConnectionManager, log logger.Logger) Repository {
 	return &repository{
-		ormRepo: orm.NewRepository[tender.Tender](mongoManager.GetCollection(tenderCollectionName()), log),
-		logger:  log,
+		ormRepo:        orm.NewRepository[tender.Tender](mongoManager.GetCollection(tenderCollectionName()), log),
+		mongoManager:   mongoManager,
+		metricsCounter: orm.NewCounter(mongoManager),
+		logger:         log,
 	}
 }