fix: balance overflow

[reez]

Description

When a balance is 9,999,709,517 sats (10 digits) the format string was causing an integer overflow because %d expects a 32-bit integer but our value exceeds the maximum 32-bit integer (2,147,483,647).

Notes to the reviewers

Changelog notice

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I have formatted my code with swift-format per .swift-format file

New Features:

• I've added tests for the new feature
• I've added docs for the new feature
• UI changes tested on small, medium, and large devices to ensure layout consistency

Bugfixes:

• This pull request breaks the existing API
• I've added tests to reproduce the issue which are now passing
• I'm linking the issue being fixed by this PR

[reez]

prob need to fix this in Monday app too