[iamnbutler]

Adds two snapshot-bound tools for controls that clicking and typing handle badly.

Tools

• desktop_element_action performs one named Accessibility action on an observed element: AXShowMenu, AXIncrement, AXDecrement, AXConfirm, AXCancel, AXPick, AXRaise or AXScrollToVisible. The client refuses before dispatch when the element doesn't list that action in attributes.actions. AXPress is left out because it duplicates desktop_click.
• desktop_set_value sets a non-text control and checks the result by reading the same element back.
  • Numbers work for sliders, steppers (AXIncrementor) and level indicators.
  • true/false works for checkboxes, switches and disclosure triangles, where true expands.
  • When a toggle's value is read-only but the toggle advertises AXPress, as SwiftUI checkboxes do, it gets at most one press. If the state already matches, nothing is sent. A mixed state is refused.
  • Text roles are refused and pointed to desktop_type.
  • Pop-up buttons are documented as: desktop_click to open, then AXPick (or a click) on the item from the next inspection. Open menus are now listed first in ui_elements, so the 32 KB result bound doesn't trim them away.
• desktop_inspect now adds attributes.actions to each element. It lists only the standard AX names, at most 16, from the supported set (AXPress is omitted).

Exactness (peekaboo-element-action.patch, last in the stack after peekaboo-layout-keys.patch from #46)

• Upstream, performAction and setValue resolved the target by snapshot ID and fell back to a fuzzy label query. They then found the live element by a score in which a label or frame alone could win. The only check afterwards compared that live element with itself.
• With the patch, both take only a literal element ID. The live element must match the observed receipt (process, window, role, frame, and identifier or title) before input and again right before the action. A mismatch is a pre-dispatch SNAPSHOT_STALE refusal.
• This also makes desktop_type stricter, since it routes through setValue.
• Named actions run off MainActor through DetachedAXActionRunner.
• Upstream test fixtures that stand in a fake AX element inject a matcher that accepts it. Two new tests cover a mismatched live element and a label used in place of an ID.
• The patch is documented in native/patches/README.md.

Verified

• Rebased onto main at 3f95dd5 (feat: send every printable key and the remaining named keys #46) with this patch last.
  • npm run build:js && npm run check passes.
  • node dist/build.js --out build --scratch native/.build passes with the full patch stack.
• Upstream PeekabooAutomationKit tests on the rebased stack: 168/168 passed for the filters ActionInputDriverTests|UIAutomationActionOutcomeProvidingTests|DetachedAXObservationWorker|AgentCursor|SetValue.
  • This includes the 2 new tests and the 4 fixture updates.
  • The run was isolated from the machine-wide ~/.peekaboo lane lock by a throwaway local edit that pointed DesktopCoordinationRuntimeRoot.defaultURL at a temp directory. The edit was reverted before pushing and is not part of this PR.
  • Setting HOME doesn't isolate the lock, because the lane root comes from the account database (getpwuid_r).
• Tested live with a signed dev build (isolated state dir), System Settings > Sound. Everything was restored: volume 31, unmuted, alert sound Boop.
  • Output volume slider: desktop_set_value 0.25 completed with readback 0.25. AXIncrement went 0.25 to 0.35 and AXDecrement went back.
  • Mute checkbox (SwiftUI, read-only value): false when already unmuted was confirmed_no_change and sent no input. true was confirmed by a press with readback; then restored.
  • Alert sound pop-up: desktop_click opened the menu, the items listed AXPick, and AXPick on the current item completed.
  • Acting on a menu item after its menu closed was correctly refused as stale. The fuzzy resolver had picked the pop-up button instead.

Pending: screen locked

The Mac's screen locked partway through, so these live checks have not run:

• AXShowMenu on a Finder file: check the context menu appears in the next inspection, then dismiss it with AXCancel.
• Finder list view disclosure triangle: desktop_set_value true/false to expand and collapse, then restore.
• TextEdit Format > Font panel stepper (AXIncrementor): AXIncrement/AXDecrement and desktop_set_value.
• Displays brightness slider: set and restore.
• Pop-up item change: pick Breeze, verify, then restore Boop.
• Regression: desktop_type into a TextEdit or Settings search field under the exact binding.
• AXConfirm, AXRaise and AXScrollToVisible on elements that advertise them.

Caveats

• Date pickers aren't supported, because UIElementValue has no date type.
• desktop_set_value compares numbers exactly on readback, so a control that rounds or snaps reports unknown. Re-inspect it rather than repeat.
• A press-toggled checkbox reports accessibility_action delivery, not accessibility_value.
• attributes.actions makes inspect results a few percent larger, still within the 32 KB bound.