feat(dashboard): add date filter and stat groups components

- Implemented DashboardDateFilter component for selecting date ranges.
- Created DashboardStatGroups component to display various dashboard statistics.
- Added dashboard chart data processing logic to support new chart specifications.
- Introduced reusable Chart components for rendering different types of charts.

Backend/ERPCore/Program.cs

@@ -231,6 +231,7 @@ builder.Services.AddScoped<IAuditService, AuditService>();
 
 // Dashboard aggregate stats (cross-domain read: stock, GRN, procurement)
 builder.Services.AddScoped<IDashboardService, DashboardService>();
+builder.Services.AddScoped<IDashboardChartsService, DashboardChartsService>();
 
 // HRM (docs/13-BACKEND-HRM-API.md): org masters, employee core, staff documents
 builder.Services.AddSingleton<IFileStorageService, LocalFileStorageService>();