Add unit tests for dashboard repository and enhance BSON handling

internal/dashboard/statistics_repository_test.go

@@ -101,7 +101,7 @@ func TestResolveScrapedTendersScopeUsesMinIOFolders(t *testing.T) {
 	}
 }
 
-func TestResolveScrapedTendersScopeZeroWhenMinIOEmpty(t *testing.T) {
+func TestResolveScrapedTendersScopeMongoFallbackWhenMinIOEmpty(t *testing.T) {
 	repo := &repository{
 		procedureLister: &mockProcedureDocumentsLister{},
 	}
@@ -110,8 +110,11 @@ func TestResolveScrapedTendersScopeZeroWhenMinIOEmpty(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	if !scope.zero {
-		t.Fatalf("expected zero scope, got %#v", scope)
+	if scope.zero {
+		t.Fatal("expected mongo fallback scope, not zero scope")
+	}
+	if scope.match["processing_metadata.documents_scraped"] != true {
+		t.Fatalf("expected mongo fallback filter, got %#v", scope.match)
 	}
 }