[iamnbutler]

Fixes #243. Fixes #245. Also covers the sheet part of #244 (an incomplete tree right after a sheet appears).

Reproduced with a new fixture, native2/fixture/sheetfix.swift: an AppKit window with a beginSheet sheet and an NSAlert sheet, and a second window hosting a SwiftUI .alert.

What was wrong

• Xcode Organizer: clicks that open or close a sheet report unknown (retry_safety unsafe) although they took effect #243: AppKit and SwiftUI answer an AXPress that opens or closes a sheet with kAXErrorCannotComplete (-25204, after about 250 ms, so it isn't a timeout), although the press worked. A standalone AX probe sometimes gets success, so it's racy, but the host hit it every time.
• Sheets: desktop_windows sends agents to a pixels-only window; the working AXSheet is only in the parent, whose screenshot omits it #245: AppKit windows don't support AXSheets. Sheets are AXSheet children of the parent window. The window server lists each sheet as its own untitled window, which matched no AX window, so it was listed as pixels_only / no_matching_accessibility_window. A SwiftUI alert's window also adds a transparent margin around the AXSheet frame (410×288 window, 260×138 sheet, same center). The parent's capture used includeChildWindows = false, so the sheet was missing from its screenshot.
• desktop_dialog listed a SwiftUI alert's buttons as [], because SwiftUI puts the title in AXDescription.
• After a click that opens a SwiftUI alert, the follow-up observation often hit "AX tree incomplete" while the tree was changing.

Changes

• Pointer.swift: when a press comes back indeterminate, it rereads the window's sheet count for up to 1 s. If the count changed, the result is completed (confirmed_change, sheet: "opened"|"closed"). Indeterminate results now carry ax_error.
• AX.swift: sheets are read from AXSheets and from AXSheet children. A sheet's window is matched by its window ID, or by containing the sheet's frame with the same center.
• desktop_windows: a sheet's own window gets observation_reason: attached_sheet and sheet_of_window_id. Its availability is unavailable / attached_sheet with parent_window_id and a hint: inspect the parent window, click there, and use desktop_dialog on the parent.
• desktop_inspect on a sheet's own window (either mode) now returns ATTACHED_SHEET right away and names the parent, with no 1 s retry and no "use pixels mode" advice. The check only runs for untitled windows.
• The parent's screenshot now draws its attached sheets, so the image matches the AXSheet elements listed.
• desktop_dialog / desktop_dialog_answer: button titles fall back to AXDescription. A sheet's own window target is refused with a message naming the parent.
• An action's follow-up observation retries once after 0.5 s when the tree is incomplete, as inspect already does.
• src/tools.ts: the desktop_windows description names attached_sheet and sheet_of_window_id. The contract is regenerated.

Checked

• swift test --package-path native2: 54 + 33 passed. npm run check is clean.
• Live on the fixture, through the standalone host built from this branch (the dev app had no Accessibility or Screen Recording grant on this Mac yet):
  • Open Sheet, Cancel, Delete, Open Alert and alert Cancel each returned completed with sheet: opened/closed. Before this change, Open Sheet returned unknown / unsafe, as the release app still does.
  • SwiftUI Show Alert followed by Cancel or Delete, three rounds: all completed, each with a fresh observation.
  • desktop_windows lists both sheet windows as attached_sheet with the right parent.
  • desktop_dialog on each parent lists the buttons, including the SwiftUI ones. On a sheet's own window it names the parent.
  • Pixels inspect of the parent shows the sheet, for both AppKit and SwiftUI.

Not changed: Xcode's own sheets weren't retested (the brief said to use the fixture).

🤖 Generated with Claude Code