Show HN: Sheetgraph, AI agents can understand complex spreadsheets

Sheetgraph is a Rust-built local binary that extracts Excel and Google Sheets files into a short REPORT.md plus a formula dependency graph, keeping every cell for exact lookups; a 120k-cell invoice ledger compresses to about 7k tokens instead of roughly 1.3M. It ships as an agent skill for Claude Code, Codex and Cursor, and supports drill-down commands (cells, trace, find) for querying specific values. It is in beta (0.1), and the report format and library API may change between releases.