Refactor UI imports and update component paths

Replaces imports from 'components/ui' with 'components/common' across the app and dashboard pages, and updates model and API imports to use new paths under 'lib'. Removes redundant authentication checks from several dashboard pages. Adds new dashboard components and utility files, and reorganizes hooks and services into the 'lib' directory for improved structure.

lib/models/products.ts

@@ -0,0 +1,19 @@
+export interface Product {
+  _id?: string;
+  name: string;
+  description: string;
+  unitType: "pcs" | "gr" | "kg" | "ml" | "oz" | "lb";
+  category: string;
+  enabled?: boolean;
+  // Stock management fields
+  stockTracking?: boolean;
+  currentStock?: number;
+  lowStockThreshold?: number;
+  stockStatus?: "in_stock" | "low_stock" | "out_of_stock";
+  pricing: Array<{
+    minQuantity: number;
+    pricePerUnit: number;
+  }>;
+  image?: string | File | null | undefined;
+  costPerUnit?: number;
+}