[datlechin]

Summary

• Themes color the data grid header, selection, inactive selection, selected text and active-cell border again: dataGrid.headerBackground, headerText, selection, inactiveSelection, selectionText and focusBorder are back, with their values in the 14 bundled themes, the Theme Editor's Selection section and the VS Code import mapping. refactor(data-grid)!: rebuild the macOS data grid on one model and native AppKit #3833 retired them and is unreleased, so no schema bump.
• One drawing path: every reader draws the resolved slot, and an unset slot resolves to its system color. The six slots have no derived or paired fallback, and ThemeFileFormat.retiredKeys is gone.
• AppKit's header cell paints its own opaque band and takes a title's color only from the title's attributes (measured on macOS 27). ThemeTableHeaderCell paints the band, divider and bottom line, then leaves the title and sort arrow to AppKit's interior drawing; ThemeTableHeaderView styles each title before a draw and bolds the highlighted column, which AppKit's highlight pass did.
• On macOS 26 and later the header sits in the scroll pocket's vibrant banner, which blended any band lighter; ThemeTableHeaderView turns vibrancy off (measured with lldb on the running grid).
• Grid: the row selection, the selected text, the active-cell border and the edit field border read the slots. The Query Plan and Users & Roles outlines get the themed header and draw the theme's selection.
• ER diagram node headers and selection, the Query Plan diagram's selected step and dashboard tile titles read their slots again.
• Changelog: drops refactor(data-grid)!: rebuild the macOS data grid on one model and native AppKit #3833's two fragments that announced the retirement; 3837.changed.md notes that a theme's missing header and selected text colors now take the system's.
• Tests changed on purpose: the theme, chrome, header, ER and Query Plan theme suites now pin the themed header and selection; the retired-key file format tests are replaced by ones that load the six keys.

Before	After

Test plan

• Unit plan: 26,617 tests pass.
• Package: TableProThemeTests 157 pass.
• Probes on macOS 27.0.1: what an NSTableHeaderCell paints and its 16 pt interior band, which title attributes AppKit honors, the copied filler cell, the highlight pass, and the header's vibrancy inside NSScrollPocket.

Docs: TableProApp/docs#127