Consolidate MONTH_NAMES, PALETTE, formatCurrency, formatCurrencyShort, ordinal, and fmt into client/src/utils/formatting.js. Consolidate CONFIG_KEYS into server/src/constants.js. All consumer files updated to import from these shared modules. PaycheckView re-exports formatCurrency, ordinal, and formatPayDate for backward compatibility with existing tests. Nightshift-Task: dead-code Nightshift-Ref: https://github.com/marcus/nightshift