Find vendor contracts whose non-renewal notice deadline is near, through amendments, month-end dates and business-day notice periods

# Which vendor contracts need a non-renewal decision soon? Inputs: `contracts.csv`, `amendments.csv` and `calendar.json` (today's date and public holidays). Today is the date in `calendar.json`. For every contract that auto-renews, find the current term's end date and the last day on which a non-renewal notice can still be given. - A term of N months starting on date S ends the day before S plus N months. If that month is shorter, S plus N months falls on its last day (so 31 January plus 1 month is 28 or 29 February). - A contract renews for its renewal term each time a term ends, so the current term is the one that contains today. Each renewal term starts on the day after the previous term ends. - Notice must arrive at least the notice period before the term ends: the deadline is the end date minus the notice period. Periods are in days, months (same month rule as above) or business days (Monday to Friday, not holidays; count back from the end date, not counting the end date itself). - Only signed amendments change a contract; a later signed amendment to the same field replaces an earlier one, by effective date. - If the current term's deadline has already passed, the contract will renew: report the next term instead (its end date and deadline). Write `out/renewals.json`: `{"contracts": {"<contract_id>": {"term_end": "YYYY-MM-DD", "notice_deadline": "YYYY-MM-DD"}, ...}, "decide_within_30_days": [<ids whose reported deadline is from today to today + 30 days inclusive, sorted>], "missed_current_term": [<ids whose current-term deadline has passed, sorted>]}`. Leave contracts that don't auto-renew out of `contracts`. ## 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.