Add more product currencies (AUD, NZD, etc.)

This consolidates related currency requests: Ugwumsinachi Nnadi (NGN), Tensor Tonic (VND — also wants MoMo/ZaloPay/VNPAY as payment methods), Huitaca Dynamics (COP), Dechax (TRY), and yanxin s (WeChat Pay/CNY — reports their dashboard only shows USD/EUR/GBP/INR despite docs mentioning WeChat/CNY support).

It is crucial for my business to be able to control the exact price customers see for my product in each specific currency. The current adaptive pricing model doesn’t work for my use case, because I need to define a fixed base price in USD while also being able to set and control, for example, the PLN price directly.

Additionally, I need the final price in the customer’s local currency (e.g., PLN) to be displayed on the invoice, rather than the base USD product price. This is important both for customer clarity and for my accounting and tax compliance.

Example:

I run an online shop that sells digital products internationally. I want to charge exactly $50 USD for a product in the US and exactly 199 PLN for the same product in Poland. With the current adaptive/exchange-rate-based pricing, the PLN amount constantly fluctuates and often ends up at non-psychological prices (e.g., 187.36 PLN instead of 199 PLN), which hurts conversion and makes marketing campaigns difficult (e.g., “Special offer: 199 PLN” can’t be guaranteed).