[datlechin]

Summary

• Every macOS data grid runs on one rebuilt grid: data and query tabs, Structure, Create Table, the Structure and dashboard lists, Compare & Sync, result comparison, Data Files, agent results, table listing and the theme preview.
• DataGridModel owns the grid's state and outlives the view: rows by RowID, columns by DataGridColumnID, one selection, sort, value filter, layout, display formats, find and the open edit. Owners talk to it through DataGridDataSource and DataGridActions; TableViewCoordinator is gone.
• Pure engines with their own tests: GridSelectionReducer, GridSelectionSnapshot, DataGridColumnSet, DataGridRowOrder, DataGridChange, GridFindEngine.
• AppKit owns what it draws best: stock NSTableHeaderView and header cells, NSTableRowView selection in the system colors, an in-cell NSTextField editor, NSEditor commit and discard through an NSViewController. Cells stay drawn with CoreText: a view per cell missed the 200-column budget.
• Frozen columns are a second table laid over the main one's leading edge; the main table keeps every column, so keyboard, find, copy and VoiceOver see one table.
• A click selects the row with the cell cursor on the cell; drag, Shift and Command make cell ranges; row numbers and Select All pick rows (GridSelection.Mode).
• Sort: a click sorts or reverses, Option-click adds a key, Don't Sort is in the header menu.
• One find bar for every grid: Match Case, Whole Words, Regular Expression, a column scope and Replace. A focused grid answers Find itself. Data Files find and Replace All cover the whole file.
• A value with a line break or over 256 characters edits in a popover anchored to the cell.
• Themes no longer color the grid header, selection, selected text or active-cell border. A theme file that still has those six keys loads with them dropped.
• Every edit, paste, Set Value, Fill Column and Replace All is one model.commit taken by IDs: one undo step, on the records it named.
• Fixed on the way: a reload left no visible selection while Delete acted on old rows; a tab or Structure sub-tab switch saved an open edit into the wrong tab; edits, deletes and pastes under a value filter landed on another row; Find Next left the cursor in the old column; a temporary table and the Structure tab wrote the table's saved layout; Display As on a query result reset after Load More; Copy Rows did nothing in a data file window; VoiceOver numbered rows from 1 on every page and never named the edited cell's column; Copy as IN Clause on a join result lost MySQL's backslash escaping.
• Grids that loaded on onChange(of:) read the previous body's values (measured on macOS 27); they load from task(id:).
• Tests changed on purpose: the selection suites (click selects the row with the cursor, Select All leaves no cursor, Escape shrinks a range to the cursor's row), HeaderSortCycleTests and HeaderSortUITests (Option-click adds a key), the theme slot suites (six slots gone), DataFileControllerTests (find waits for the whole-file search). Suites that tested TableViewCoordinator were deleted or ported to TableProTests/Core/DataGrid and TableProTests/Views/DataGrid.

Before	After

Test plan

• Unit plan: 26,566 tests pass locally.
• UI plan: passes on CI, GridFindUITests included; not run locally, since XCUITest cannot start beside the TablePro already running on this Mac.
• Lint on all 342 changed Swift files.
• Probes measured: drawn cells against a view per cell at 200 columns, the frozen overlay's scroll sync, NSEditor on NSViewController, onChange(of:) against task(id:) captures, the accessibility element of an NSTextField, NSTableView pixel-aligning a fractional column width.

Docs: TableProApp/docs#127