Add translated notices scanning functionality to dashboard repository

- Introduced a new `translatedNoticesScanner` interface for scanning MinIO for daily translated notice counts.
- Enhanced the `repository` struct to include fields for managing translated notice scope and caching.
- Implemented the `ScanTranslatedNotices` method in the `StorageClient` to retrieve daily counts and total from MinIO.
- Updated the `Statistics` method in the repository to utilize the new translated notices scope, improving data accuracy.
- Added unit tests for the translated notices functionality, ensuring robust validation of the new features.

This update significantly enhances the dashboard's ability to handle translated notice statistics, improving overall data management and reporting capabilities.

internal/dashboard/repository.go

@@ -27,6 +27,11 @@ type scrapedDocumentsScanner interface {
 	ScanScrapedDocuments(ctx context.Context) ([]ai_summarizer.ProcedureDocumentsSummary, map[string]int64, error)
 }
 
+// translatedNoticesScanner optionally scans MinIO for per-day translated notice counts.
+type translatedNoticesScanner interface {
+	ScanTranslatedNotices(ctx context.Context) (map[string]int64, int64, error)
+}
+
 const defaultValueCurrency = "EUR"
 
 // Repository defines dashboard data access.
@@ -51,6 +56,11 @@ type repository struct {
 	scrapedScopeExpiry   time.Time
 	scrapedScopeCached   bool
 	scrapedScopeGroup    singleflight.Group
+	translatedScopeMu     sync.Mutex
+	translatedScope       translatedNoticesScope
+	translatedScopeExpiry time.Time
+	translatedScopeCached bool
+	translatedScopeGroup  singleflight.Group
 }
 
 // NewRepository creates a dashboard repository backed by the tenders collection.