Numeric fees in consistent format

Mixed fee formats — $0.50 on pricing, .5 USD at checkout, 0.50 on statements — make users second-guess the amount and erode trust at the exact moments they are deciding whether to pay. Inconsistent decimal precision is also a reconciliation hazard: a fee rendered $10 on the pricing page and $10.00 on the invoice looks fine to humans but breaks downstream CSV parsers and accounting imports. The content-integrity taxon captures both the user-facing confusion and the data-quality drift across surfaces.

Centralize every fee render through a single Intl.NumberFormat helper so currency symbol, decimals, and thousands separators are locked site-wide. Create src/lib/formatters.ts and import it anywhere money is displayed:

export function formatFee(amount: number, currency = 'USD') {
  return new Intl.NumberFormat('en-US', {
    style: 'currency',
    currency,
    minimumFractionDigits: 2,
  }).format(amount);
}

Then grep the repo for $ and .toFixed( and replace each with formatFee().