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.

Frontend/erp-system/lib/api/dashboard.ts

@@ -1,9 +1,15 @@
 // Dashboard overview endpoint (Backend/ERPCore/Controllers/DashboardController.cs).
 import { apiRequest, buildQuery } from "@/lib/api-client"
-import { DashboardStats } from "@/types/dashboard"
+import { DashboardChartsData, DashboardStats } from "@/types/dashboard"
 
 export const dashboardApi = {
-  stats(params: { branchId?: number } = {}): Promise<DashboardStats> {
+  /** `from` / `to` (YYYY-MM-DD) set the period for the activity counts; omitted means today. */
+  stats(params: { branchId?: number; from?: string; to?: string } = {}): Promise<DashboardStats> {
     return apiRequest<DashboardStats>(`/dashboard/stats${buildQuery(params)}`)
   },
+
+  /** Datasets for the dashboard graphs; the time-based ones follow `from` / `to` (YYYY-MM-DD, default today). */
+  charts(params: { branchId?: number; from?: string; to?: string } = {}): Promise<DashboardChartsData> {
+    return apiRequest<DashboardChartsData>(`/dashboard/charts${buildQuery(params)}`)
+  },
 }