dsh-extension-workbook

When an AI assistant glances at an Excel workbook, the result is often a vague summary with no guarantee that formatting survived or formulas were left untouched. dsh-extension-workbook takes a harder stance: it ships a set of high-fidelity .xlsx and .xlsm tools for inspection, rendering, editing, diffing, and validation, where every step is traceable and any operation the engine cannot handle with byte-level fidelity is rejected outright rather than silently downgraded.

The core workflow is fail-closed and verifiable by design. Inspection and deterministic PNG rendering leave the source file untouched; edits go through a guarded pipeline of dry-run planning, expectedSha256 conflict checks, atomic writes, and post-commit validation, with a recovery copy retained for in-place edits. Workbook diffs validate structural integrity before results are accepted. Protected content such as VBA macros is inventoried and verified but never executed. Model-visible output is capped; oversized JSON is written to a temporary artifact whose path is returned, so nothing is truncated.

It is well suited for scenarios where a user reviews or corrects spreadsheets inside a chat conversation yet has hard requirements on data integrity and auditability: financial reconciliation, report-format validation, cross-version diffing, and similar tasks. The upstream skill and documentation from @firstpick/pi-extension-workbook are kept verbatim; every adaptation in this port is itemised in THIRD_PARTY_NOTICES.md for easy traceability.