fix: correct 7 gold answers and remove 3 bad questions
Gold corrections:
- finance_q224: fix date from 2026-03-10 to 26-03-10 (1925 tax receipt)
- finance_q238: state=D is a postcode label not a state entry → state=null
- finance_q206: labor_amount 9935 → 99.35 (missing decimal)
- medical_healthcare_q57: urine checkbox is checked → true
- medical_healthcare_q4: codes are -7/-8 (circled), not 77/98 → 7/8
- medical_healthcare_q5: neither value circled → self_pay_value=null
- mortgage_q391: item l is 'No' not 'Yes'
Removed questions:
- finance_q355: unreadable text, misleading 'gotcha' question
- mortgage_q352: misaligned column/row mapping, inconsistent gold
- finance_q14: nonsensical question (Evidence is a sibling field, not umbrella)