Split a shared house's tiered gas and electricity bills by days in the house, with unit conversion and leftover pennies

# Split a shared house's energy bills between housemates who came and went Inputs: `bills.csv` (bill_id, fuel, from, to, opening_read, closing_read), `housemates.csv` (name, move_in, move_out), `tariff.json` and `landlord-note.txt`. Amounts are in pounds. `tariff.json` and these rules are the record; where the landlord's note disagrees, the rules win. Rules: - A bill covers from to to, both days included. Units used = closing_read - opening_read; gas meters read in cubic metres, so gas kWh = units x volume_correction x calorific_value / kwh_divisor. - Each bill's first low_rate_kwh_per_day x (days in the bill) kWh are charged at low_rate and the rest at high_rate; add standing_per_day for every day; then add vat_pct percent. The bill total is rounded half-up to 0.01. - A housemate is in the house from move_in to move_out, both days included (blank move_out means still living there). Each bill total is split in proportion to each housemate's days in the house during that bill. - Each share is rounded half-up to 0.01; any penny difference between the shares and the bill total goes to the housemate with the most days in that bill (ties: first name alphabetically). - Write `out/split.json`: `{"kwh": {"<bill_id>": <kWh, 2 decimals>, ...}, "bill_totals": {"<bill_id>": <total>, ...}, "per_bill_shares": {"<bill_id>": {"<name>": <share>, ...}, ...}, "shares": {"<name>": <sum of their shares>, ...}}`. Per-bill shares list only housemates with at least one day in that bill; `shares` lists every housemate. ## 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.