xlsx-engineer

[production-grade internal] Creates, edits, analyzes, and validates Excel spreadsheet files (.xlsx, .csv, .tsv). Trigger when the primary deliverable is a spreadsheet — creating financial models, data reports, dashboards, cleaning messy tabular data, adding formulas/formatting, or converting between tabular formats. Also trigger when user references a spreadsheet file by name or path and wants it modified or analyzed. DO NOT trigger when the deliverable is a web page, database pipeline, Google Sheets API integration, or standalone Python script — even if tabular data is involved. Routed via the production-grade orchestrator (Feature/Custom mode).