[Bug] JMD Currency Precision — Mobile

[islandbitcoin]

JMD Currency Precision — Mobile Fixes

Mobile-side bugs that cause incorrect JMD display for users. Backend fixes (ENG-132) should land first so mobile can validate against correct data.

Checklist

• Transaction list reconverts at current price instead of using settlementDisplayAmount from API (High)
• Breez SDK transactions hardcode USD display currency (High)
• JMD display currency precision umbrella (High)

PR Review: Nick reviews, Dread approves before merge.

[linear]

ENG-138