feat: added balance ₿-only format(bip177)

[r1b2ns]

Description

This PR added ₿-only format on balance screen view and resolve the issue

Reference
https://bitcoin.design/guide/designing-products/units-and-symbols/#sample-mockups

Screens

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

[reez]

looking pretty good so far.

The implementation uses "1K", "1M" notation which differs from BIP177's actual proposal. BIP177 suggests displaying sats as integers with thousand separators (e.g., "₿10,000" not "10K").

[r1b2ns]

Nice, @reez. I was following these samples to create the 1k and 1M notation logic.

'''
Examples #
Examples of how legacy bitcoin quantities would be represented under this new convention:

0.00000100 BTC -> ₿100
0.00005449 BTC -> ₿5,449
3.25 BTC -> ₿325,000,000 or ₿325M
15,000 sats -> ₿15,000 or ₿15K
'''

I little confused, Wouldn’t we use this notation?

[reez]

ACK 6fdb931

This is perfect actually.

My b, you're totally right, I was getting tripped up on 15,000 sats -> ₿15,000 **or** ₿15K part, but I see you have it implemented nicely handling this where ₿15K when representing 15,000 sats and then shows ₿15,123 when representing 15,123 sats

I'll merge this (and any other open PRs) after I merge #302 (later this week hopefully when bdk-ffi/swift 2.0 is released).

[r1b2ns]

Awesome, @reez i'll implement it on Monday app too

[reez]

Awesome, @reez i'll implement it on Monday app too

great! I'll merge that one as soon as I see it