The client had ~15 hand-rolled currency formatters (local `fmt`/`money`/
`fmtFull`/`fmtDollars`/…) plus a canonical `fmt` in lib/utils used at ~190
sites — same rules copy-pasted, with inconsistent handling of negatives,
whole-dollar, cents vs dollars, and blank input.
Add client/lib/money.js as the one implementation:
- formatUSD(dollars) — "$1,234.56" (whole/dash options)
- formatUSDWhole(dollars) — "$1,235"
- formatCentsUSD(cents) — from integer cents; signed "+/-" and dash options
Inputs are coerced so null/''/NaN never render as "$NaN", and -0 is
normalized so it never shows as "-$0.00".
lib/utils.fmt now delegates to formatUSD (byte-identical — the existing
utils.test.js fmt suite is the regression guard), and the 15 local
formatters delegate to money.js. No display currency formatting remains
outside money.js; the /100 conversions left behind are calculations
(form prefill), not display.
Tests: client/lib/money.test.js (13). Full client suite 46 pass; build clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>