Use the xlsx Skill.

Create an Excel trading workbook from the two weekly rows supplied. Include an editable input sheet, formula-based summary and a short guide. Calculate net revenue, conversion rate, average order value, ad-spend ratio and week-on-week changes. Recalculate and check the saved values, then create a second what-if workbook with current orders changed to 150 while the other inputs remain unchanged.

The attached business materials are:
- inputs/weekly.csv

Deliver a complete result.md report that the operations team can read, plus any finished files needed for this task. Keep supporting calculations and evidence with the deliverables. Write the report in English; use the requested target language for customer-facing copy. The business datasets are fictional examples unless the brief explicitly names a live public website.