Fiat conversion

[charlesejemai-cyber]

Summary

Add fiat conversion display using the Reflector oracle. This introduces inline fiat values (≈ $x) for asset amounts in Activity, Send, and Receive, adds a configurable fiat currency setting (USD/EUR/GBP/NGN), caches prices for 60 seconds, and gracefully hides fiat values when the oracle is unavailable.

closes #113

[vercel]

@charlesejemai-cyber is attempting to deploy a commit to the truthixify's projects Team on Vercel.

A member of the Team first needs to authorize it.

[drips-wave]

@charlesejemai-cyber Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[truthixify]

build step failing on "Unable to locate executable file: pnpm" because your branch predates the corepack pin in ci.yml on develop. Rebase against latest develop and force-push, that will pull in the corepack step and pnpm will be found.

[truthixify]

Still blocked by merge conflicts. Please rebase on latest develop and resolve conflicts. Vercel is non-blocking.