feat: add dashboard overview stats endpoint and UI integration

- Implemented `GET /dashboard/stats` in `DashboardController` to provide aggregate counts for stock, GRN, and procurement.
- Created `DashboardStatsDto` and `WarehouseValuationDto` to structure the response data.
- Developed `DashboardService` to fetch and compute necessary statistics from the database.
- Added `IDashboardService` interface for service abstraction.
- Introduced API client methods in `dashboard.ts` for frontend consumption of the new endpoint.
- Defined TypeScript types for dashboard data in `dashboard.ts` to ensure type safety in the frontend.
- Updated UI components in the frontend to reflect changes in the dashboard, including styling adjustments and removal of unused icons.

Backend/ERPCore/Controllers/DashboardController.cs

@@ -0,0 +1,20 @@
+using ERPCore.Dtos.Dashboard;
+using ERPCore.Services.Interfaces;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ERPCore.Controllers;
+
+/// <summary>Dashboard overview stats — cross-domain counts, not a stored entity.</summary>
+[Route("api/v1/dashboard")]
+public sealed class DashboardController : ApiControllerBase
+{
+    private readonly IDashboardService _dashboard;
+
+    public DashboardController(IDashboardService dashboard) => _dashboard = dashboard;
+
+    /// <summary>Aggregate counts for stock, GRN, and procurement.</summary>
+    [HttpGet("stats")]
+    [ProducesResponseType(typeof(DashboardStatsDto), StatusCodes.Status200OK)]
+    public async Task<ActionResult<DashboardStatsDto>> GetStats(CancellationToken ct)
+        => Ok(await _dashboard.GetStatsAsync(ct));
+}