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/Services/DashboardService.cs

@@ -0,0 +1,79 @@
+using ERPCore.Domain.Entities;
+using ERPCore.Domain.Enums;
+using ERPCore.Dtos.Common;
+using ERPCore.Dtos.Dashboard;
+using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Interfaces;
+using Microsoft.EntityFrameworkCore;
+
+namespace ERPCore.Services;
+
+/// <summary>
+/// Aggregate counts pulled straight from each domain's repository — no PagedResponse
+/// overhead, since the dashboard only needs totals. Low-stock reuses <see cref="IReorderService"/>
+/// rather than re-deriving the FIFO-available-vs-reorder-point comparison (docs/11 §5.7).
+/// On-hand summary and stock valuation sum <see cref="StockLayer.QtyRemaining"/> (and
+/// QtyRemaining × UnitCost for valuation) directly in SQL — cheap, unlike reorder alerts,
+/// because they need no per-item live lookup.
+/// </summary>
+public sealed class DashboardService : IDashboardService
+{
+    private readonly IRepository<StockLayer> _layers;
+    private readonly IRepository<Grn> _grns;
+    private readonly IRepository<PurchaseOrder> _pos;
+    private readonly IRepository<Requisition> _requisitions;
+    private readonly IRepository<StockCount> _counts;
+    private readonly IRepository<Rfq> _rfqs;
+    private readonly IReorderService _reorder;
+
+    public DashboardService(
+        IRepository<StockLayer> layers, IRepository<Grn> grns, IRepository<PurchaseOrder> pos,
+        IRepository<Requisition> requisitions, IRepository<StockCount> counts, IRepository<Rfq> rfqs,
+        IReorderService reorder)
+    {
+        _layers = layers;
+        _grns = grns;
+        _pos = pos;
+        _requisitions = requisitions;
+        _counts = counts;
+        _rfqs = rfqs;
+        _reorder = reorder;
+    }
+
+    public async Task<DashboardStatsDto> GetStatsAsync(CancellationToken ct = default)
+    {
+        // Sequential, not Task.WhenAll: these repositories share one scoped DbContext,
+        // which cannot run concurrent operations.
+        var onHandTotal = await _layers.Query().AsNoTracking().SumAsync(l => (decimal?)l.QtyRemaining, ct) ?? 0m;
+        var onHandWarehouses = await _layers.Query().AsNoTracking()
+            .Select(l => l.WarehouseId).Distinct().CountAsync(ct);
+        var stockValuationTotal = await _layers.Query().AsNoTracking()
+            .SumAsync(l => (decimal?)(l.QtyRemaining * l.UnitCost), ct) ?? 0m;
+        // EF can't translate constructing WarehouseValuationDto directly inside the GroupBy
+        // Select — project to an anonymous type first, then materialize into the record.
+        var stockValuationByWarehouseRaw = await _layers.Query().AsNoTracking()
+            .GroupBy(l => l.WarehouseId)
+            .Select(g => new { WarehouseId = g.Key, Total = g.Sum(x => x.QtyRemaining * x.UnitCost) })
+            .OrderByDescending(w => w.Total)
+            .ToListAsync(ct);
+        var stockValuationByWarehouse = stockValuationByWarehouseRaw
+            .Select(w => new WarehouseValuationDto(w.WarehouseId, w.Total))
+            .ToList();
+        var pendingGrns = await _grns.Query().AsNoTracking().CountAsync(g => g.Status == GrnStatus.Draft, ct);
+        var pendingApprovalPOs = await _pos.Query().AsNoTracking()
+            .CountAsync(p => p.Status == PurchaseOrderStatus.PendingApproval, ct);
+        var openRequisitions = await _requisitions.Query().AsNoTracking()
+            .CountAsync(r => r.Status == RequisitionStatus.Submitted, ct);
+        var pendingCounts = await _counts.Query().AsNoTracking()
+            .CountAsync(c => c.Status == CountStatus.Counted, ct);
+        var openRfqs = await _rfqs.Query().AsNoTracking().CountAsync(r => r.Status == RfqStatus.Open, ct);
+
+        // PageSize:1 is enough — GetAlertsAsync computes the full alert count before paging.
+        var lowStockAlerts = (await _reorder.GetAlertsAsync(null, new PageQuery { Page = 1, PageSize = 1 }, ct))
+            .Pagination.TotalItems;
+
+        return new DashboardStatsDto(
+            lowStockAlerts, onHandTotal, onHandWarehouses, stockValuationTotal, stockValuationByWarehouse,
+            pendingApprovalPOs, pendingGrns, openRequisitions, pendingCounts, openRfqs);
+    }
+}

Backend/ERPCore/Services/Interfaces/IDashboardService.cs

@@ -0,0 +1,9 @@
+using ERPCore.Dtos.Dashboard;
+
+namespace ERPCore.Services.Interfaces;
+
+/// <summary>Cross-domain aggregate stats for the dashboard overview.</summary>
+public interface IDashboardService
+{
+    Task<DashboardStatsDto> GetStatsAsync(CancellationToken ct = default);
+}