@eristack/spreadsheet-operator

@eristack/spreadsheet-operator headless Excel-like keyboard machine: createSpreadsheetOperator(config) with registerGrid({ id, rowCount, colCount, cellAt → { kind editable|select|display|readonly, fieldKey } }), dispatch/handleKeyDown, state inactive → active → editing, effects startEdit/commit { fieldKey }/cancel, getNextEditableAddress. Defaults: Tab wraps, arrows stop at edges, Enter edits then commits and moves down, type-to-edit, arrows in edit move the caret. Use for in-browser grids with one active grid per scope; commit → qups patchLine in the app. Not xlsx export (spreadsheet-render) and not HTTP lists (data-grid).