Feature: Add Price List support for Sales Orders

Summary

Sales Orders currently do not support Price Lists. There is no way to apply customer-specific pricing, and prices are not properly converted when a Sales Order uses a currency different from the product's base currency.

Problem

• Customers cannot be given special or negotiated pricing.
• There is no way to define different prices for different currencies.
• When a Sales Order is created in a currency other than the company's base currency, the price shown is incorrect.
• Users end up manually correcting prices on every order, which is time-consuming and error-prone.

Proposed Solution

Add a proper Price List feature for Sales, with the following behavior:

1. Users should be able to create and manage Price Lists.
2. A Price List should be assignable to a customer.
3. When a Sales Order is created for a customer with an assigned Price List, the correct price should be applied automatically.
4. If the Sales Order currency is different from the product's base currency, the price should be converted automatically using the correct exchange rate.
5. The price should update automatically whenever the customer, product, or currency is changed on the order.

Why This Matters

Without this, businesses selling to customers in different currencies or with different pricing agreements have no reliable way to get correct prices on Sales Orders, and must fix every order manually.

Scope

Sales Orders / Quotations, Price List feature