Add Purchase Order Management to Accounting System

[sweep-ai]

This pull request was created by Sweep to resolve the following request by @curtisdelicata:

Description: Implement a system for managing purchase orders from vendors.

Tasks:
Create PurchaseOrder model and migration.
Develop UI for creating and managing purchase orders.
Link purchase orders to vendors and expenses.
Acceptance Criteria:
Users can create and manage purchase orders.
Purchase orders are linked to vendor expenses.

Continue chatting at https://sweep-chat-demo.vercel.app/c/db3cba21-f281-4bf5-9ba3-6aff2b51f393.

Purpose

Implement a comprehensive Purchase Order management system to enhance the accounting workflow, allowing businesses to track and manage their procurement processes more effectively.

Description

This pull request introduces a complete Purchase Order management feature to the Liberu Accounting system. The implementation includes:

• Creation of database migrations for purchase_orders and purchase_order_items tables
• Development of Eloquent models for Purchase Orders with robust relationship definitions
• Filament resource for managing Purchase Orders with a user-friendly interface
• Integration with existing models like Suppliers and Transactions
• Automatic generation of unique Purchase Order numbers
• Comprehensive status tracking for purchase orders

The new feature allows users to:

• Create purchase orders with detailed line items
• Track order status (draft, sent, received, cancelled)
• Link purchase orders to suppliers
• Manage expected delivery dates and total amounts
• Generate sequential purchase order numbers automatically

Summary

• Added new database migrations: purchase_orders and purchase_order_items
• Created models: PurchaseOrder, PurchaseOrderItem
• Updated Transaction model to support purchase order relationships
• Implemented PurchaseOrderResource in Filament for management
• Added automatic PO number generation
• Supported multiple purchase order statuses
• Integrated with existing supplier and transaction models