Adds groupDigits(), a display-only formatter that inserts the current
locale's digit-grouping separators into an amount's integer part (e.g.
"1,000,000.5" in en-US vs "1.000.000,5" in de-DE, where the roles of ","
and "." are swapped, or hi-IN's irregular "12,34,567"). Delegates to each
platform's native locale APIs (java.text.NumberFormat/DecimalFormatSymbols,
NSNumberFormatter/NSLocale, Intl.NumberFormat with BigInt for arbitrary
precision) rather than reimplementing grouping rules, and never touches the
canonical '.'-decimal strings the rest of the app parses and stores.
Applied via a Compose VisualTransformation (BTC/Sats/fiat/manual-rate
fields, plus the read-only rate display) and, on the native SwiftUI screen,
by re-deriving the field's displayed text on every change. Also made input
parsing locale-aware: sanitizeDecimalInput now recognizes the locale's own
decimal separator (e.g. what a locale-aware decimal keypad sends), not just
"." — with a stricter rule on the SwiftUI side specifically, since its
single text buffer re-feeds the grouped display back through sanitize, so
a "." can be grouping noise there rather than a decimal point.
The exceeds-max-supply warning's "21,000,000 BTC" is no longer baked into
the localized string with hardcoded grouping; it's substituted in at
runtime via groupDigits so the link-detection text always matches exactly,
in every locale.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QpjMKWGoiT5aJBzhxvXkwp
tyiuandClaude Sonnet 5
5587428ca7