feat(dashboard): implement customizable dashboard with widget support

- Added `react-grid-layout` for drag-and-drop functionality.
- Created `DashboardCanvas` component to manage layout and widget interactions.
- Introduced `WidgetContainer` and `WidgetPicker` components for widget management.
- Implemented various widgets: Active Rides, Today Sales, Pending Purchase Orders, Stock Alerts, Recent Orders, and Loading Sheets.
- Integrated API calls for fetching and saving dashboard preferences.
- Defined default layouts for different user roles.
- Created a card component for consistent widget styling.

distribution_fe/app/(dashboard)/page.tsx

@@ -1,8 +1,5 @@
+import { DashboardCanvas } from '@/components/dashboard/dashboard-canvas'
+
 export default function DashboardPage() {
-  return (
-    <div className="flex flex-col gap-4">
-      <h1 className="text-2xl font-semibold text-foreground">Dashboard</h1>
-      <p className="text-muted-foreground">Welcome to the Distribution ERP.</p>
-    </div>
-  )
+  return <DashboardCanvas />
 }