Audit a fleet's fuel-card transactions into litres, distance and consumption per vehicle-month

# Fleet fuel audit: litres, distance and consumption per vehicle per month Inputs: `vehicles.csv`, `fuel.csv` (fuel-card transactions), `odometer.csv` (monthly odometer readings). Rules: - Vehicle ids are case-insensitive and may carry stray spaces; treat "vh-012 " and "VH-012" as the same vehicle. Report ids in upper case. - A transaction with the same vehicle, timestamp, quantity and unit as an earlier row in fuel.csv is a repost of it: keep only the first. duplicates_removed = number of rows dropped this way. - Quantities in `gal` are US gallons (1 gal = 3.785411784 L). Stations in DE, FR, NL, IT and ES write decimals with a comma ("45,30" = 45.30). - A transaction belongs to the month of its local date in the vehicle's depot time zone (`depot_tz`); ts_utc is in UTC. - Distance for a month = end_reading - start_reading from odometer.csv, in the vehicle's odometer_unit; convert miles to km with 1 mi = 1.609344 km. - litres and km per vehicle-month are rounded half-up to 2 decimals from the exact sums; l_per_100km = exact litres / exact km x 100, rounded half-up to 2 decimals. - over_tank = ids of the kept transactions whose litres are strictly more than the vehicle's tank_l, sorted. - fleet_litres = exact total litres of all kept transactions, rounded half-up to 2 decimals. Write `out/fleet.json`: `{"vehicles": {"<VEHICLE_ID>": {"<YYYY-MM>": {"litres": <n>, "km": <n>, "l_per_100km": <n>}, ...}, ...}, "over_tank": [<txn_id>, ...], "duplicates_removed": <int>, "fleet_litres": <n>}` Cover every vehicle-month present in odometer.csv (months 2026-09 to 2026-11). Numbers are checked to within 0.005. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.