settings-and-mileage-rates

name	settings-and-mileage-rates
description	Documents mileage_rates schema, rate_micro_per_mile conversion, and settings UI for IRS per-year rates in simple-books. Use when editing mileage rates, trip calculations, or /settings.

Settings and mileage rates

Schema

mileage_rates(tax_year PK, rate_micro_per_mile, updated_at)

• rate_micro_per_mile = cents_per_mile × 10_000 (72.5¢ → 725000)
• Helpers: src/lib/mileage-rates.ts

Server

• src/server/settings.functions.ts — listMileageRates, upsertMileageRate, getMileageRateForDate
• createMileage resolves rate by trip date year, stores snapshot on entry

UI

• /settings — edit rates per tax year
• Mileage dialog pre-fills rate when trip date changes

Seed

scripts/seed.ts — IRS defaults 2023–2026 (idempotent).

Mileage journal posting: accounting-posting.