Enhance dashboard statistics repository with scraped tenders scope resolution

- Introduced a new `scrapedTendersScope` type to encapsulate the MongoDB filter for tenders with scraped documents, improving clarity and maintainability.
- Updated the `Statistics` method to utilize the new scope resolution, allowing for more accurate data retrieval based on the presence of scraped documents.
- Implemented multiple tests for the `resolveScrapedTendersScope` method, ensuring correct behavior for various scenarios, including empty and fallback cases.

This update enhances the dashboard's ability to manage scraped document statistics, improving overall data accuracy and system performance.

internal/dashboard/statistics_repository_test.go

@@ -6,6 +6,8 @@ import (
 	"testing"
 
 	"tm/pkg/ai_summarizer"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
 )
 
 type mockProcedureDocumentsLister struct {
@@ -72,3 +74,58 @@ func TestScrapedDocumentsFolderIDsPropagatesError(t *testing.T) {
 		t.Fatal("expected error")
 	}
 }
+
+func TestResolveScrapedTendersScopeUsesMinIOFolders(t *testing.T) {
+	repo := &repository{
+		procedureLister: &mockProcedureDocumentsLister{
+			procedures: []ai_summarizer.ProcedureDocumentsSummary{
+				{ContractFolderID: "PROC-1", DocumentCount: 2},
+			},
+		},
+	}
+
+	scope, err := repo.resolveScrapedTendersScope(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if scope.zero {
+		t.Fatal("expected non-zero scope")
+	}
+	in, ok := scope.match["contract_folder_id"].(bson.M)
+	if !ok {
+		t.Fatalf("expected contract_folder_id filter, got %#v", scope.match)
+	}
+	ids, ok := in["$in"].([]string)
+	if !ok || len(ids) != 1 || ids[0] != "PROC-1" {
+		t.Fatalf("unexpected folder IDs: %#v", in["$in"])
+	}
+}
+
+func TestResolveScrapedTendersScopeZeroWhenMinIOEmpty(t *testing.T) {
+	repo := &repository{
+		procedureLister: &mockProcedureDocumentsLister{},
+	}
+
+	scope, err := repo.resolveScrapedTendersScope(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !scope.zero {
+		t.Fatalf("expected zero scope, got %#v", scope)
+	}
+}
+
+func TestResolveScrapedTendersScopeMongoFallbackWithoutLister(t *testing.T) {
+	repo := &repository{}
+
+	scope, err := repo.resolveScrapedTendersScope(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if scope.zero {
+		t.Fatal("expected mongo fallback scope")
+	}
+	if scope.match["processing_metadata.documents_scraped"] != true {
+		t.Fatalf("expected mongo fallback filter, got %#v", scope.match)
+	}
+}