Data Analysis Skill Overview This skill analyzes user-uploaded Excel/CSV files using DuckDB — an in-process analytical SQL engine. It supports schema inspection, SQL-based querying, statistical summaries, and result export, all through a single Python script. Core Capabilities - Inspect Excel/CSV file structure (sheets, columns, types, row counts) - Execute arbitrary SQL queries against uploaded data - Generate statistical summaries (mean, median, stddev, percentiles, nulls) - Support multi-sheet Excel workbooks (each sheet becomes a table) - Export query results to CSV, JSON, or Markdown - H…