fix(payments-next): Use currency config Because:
commit c3e08618d2bec5e64615547db1d37db489d66ea6 Author: Davey AlvarezDate: Tue Jan 6 13:25:42 2026 -0800 fix(payments-next): Use currency config Because: * Currencies were defined both in a global/importable variable and in an environment config, causing inconsistent behavior This commit: * Removes the variable, and switches referencing code to the config Closes #PAY-3432