Check and pay staff mileage claims across the April tax-year change

# Check and pay staff mileage claims across the tax-year change Inputs: `claims.csv` (claim_id, employee_id, trip_date, from, to, miles, passengers, submitted_on), `employees.json`, `rates.json` and `finance-note.txt`. Amounts are in pounds. `rates.json` and these rules are the record; where the finance note disagrees, the rules win. Rules: - A claim submitted more than late_after_days days after its trip_date is rejected as late; it is listed only in rejected_late, even if it is also a duplicate. - Two remaining claims are duplicates if they have the same employee_id, trip_date, from and to (from and to compared ignoring letter case and extra spaces); only the one submitted first is paid (on a tie, the lower claim number), and the others are duplicates. - Business miles are paid at rate_first per mile until the employee's miles in that tax year reach threshold_miles, then at rate_after; a tax year runs from 6 April to 5 April. Count paid claims in trip_date order (ties by claim number), starting from miles_before_2025_26 for the 2025-26 tax year and from 0 for 2026-27; a claim that crosses the threshold is split. - Each passenger adds passenger_per_mile for every mile of the claim; passenger miles don't count toward the threshold. - Write `out/mileage.json`: `{"paid": {"<claim_id>": <pay>, ...}, "rejected_late": [<claim_ids>], "duplicates": [<claim_ids>], "employee_totals": {"<employee_id>": <sum of pay>, ...}}`. `paid` has every paid claim; lists are sorted by claim number; `employee_totals` lists employees with at least one paid claim. ## 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.