First focused candidate: draft #120, verified focus before `AXPress` for writable editable fields. Normal button and coordinate paths retain their behavior. It also moves the native focus write off MainActor while keeping its lane owned, and preserves ambiguous completion so it cannot fall through to a second input.

Final source `4ec5802` passed types/lint, Swift parsing, independent source review, patch application/reversal and a signed build with strict app/client signatures. Real native inventory found the fresh WebKit fixture, then `listWindows` refused with `permissionDenied`. That operation requires Accessibility, so this establishes the isolated app's missing Accessibility grant; Screen Recording was not reached or tested. No focus/input was sent, no grants were requested or changed, and the fixture/runner are stopped.

The reusable validation checkout is `desktop-app-state/ace2`, app identity `dev.ace.desktop.dev.4472239c`. Reusing that checkout across future native candidates avoids adding another app identity for every PR. The bounded fixture is ready to verify actual focus, an already-focused no-op, a normal button, stale-bounds refusal and pre-dispatch cancellation. This PR remains draft until those live checks pass. Coordinate occlusion, type/paste and the window-focus timeout in this issue remain open.

Merged #120 from reviewed/signed `9374d8` after green CI. Single element clicks now verify focus on editable text fields before trying AXPress, with the write off the main actor so Ace can service its own request.

Real native focus/no-op/button and pre-dispatch cancellation checks passed. A real OpenAI channel performed inspect → one focus → inspect; exact stored results/images and usage survived worker exit/reopen without another native call. The actual isolated Ace composer also changed from unfocused to focused with its default draft and empty history unchanged.

Remaining limits are explicit: the old stale-window classification conservatively reported unknown before the new focus path, first inspection of fresh WebKit still needed a later read (#64), and in-flight cancellation was not claimed. A separate one-shot self-target point-click baseline returned 'No pressable accessibility element' (no text change), so element focus does not establish coordinate clicking. #106 remains open. #122 is next for live clipboard validation; #131 is a draft containing-window resolver fix awaiting a matching reproduction and runtime proof.

Merged #131 as `39a17ad` after green CI, independent review, and a matching real WebKit reproduction. The old signed bridge reported a visible Web count button as occluded and recorded zero clicks. The patched signed bridge resolved its native containing-window link and delivered one background Accessibility action; the actual button callback changed from 0 to 1. The editor text and unrelated input/counters stayed unchanged, and all owned runtimes/fixtures are stopped.

Together with #120, this lands verified editable element focus and the external WebKit button’s coordinate-occlusion fix. It does not establish composer point-focus, background Cmd+V, or every pointer route; those #106 items remain open. #132 normal quit is now in finite live validation, and #122 plain-text clipboard resumes immediately afterward. Desktop use remains serialized.

Final combined-source dogfood check passed in the actual Ace composer. The signed `c64042b` candidate has exactly the same repository tree as merged main `2c36c49`. In one disposable channel, explicit activation followed by one native element focus and one `desktop_insert` produced the exact public Unicode/multiline draft and UTF-16 caret. Native consumption was observed, clipboard cleanup was restored, and ownership was released. Channel history stayed empty and unchanged after reopening; no message was sent.

The original clipboard was privately restored. All six owned supervisor/host/launcher/GUI/worker/vault processes are gone, the port/socket and temporary project/channel are removed, and the existing paste gate is empty. No installed app or OS grant was changed.

This verifies the active-Ace element-focus → dedicated literal-insertion workflow. It does not claim general background `desktop_key` Cmd+V, composer coordinate-focus, direct full-value `desktop_type`, or other remaining #106 cases are fixed. #8 remains open for the remaining slices.

Merged #141 (`ad31506695d632174b3486910b73e187d6c9444c`): ordinary point clicks now use verified focus when the first actionable target is an editable Accessibility field. Native hit-testing runs away from the GUI main actor, and the exact target/window is checked again before mutation.

The signed `75f20cc96a253383cbae0647cea3bc29bb244919` candidate passed an actual-Ace check: one coordinate click focused the Message field, the `ace ` draft and caret stayed unchanged, and the empty channel history remained unchanged after a distinct worker exited and reopened it. No typing, paste, clipboard access or message submission was used. All owned runtimes, temporary channel/project and settings were cleaned up. Static checks, signed build and CI passed.

The earlier unknown point result and separate validation-runner startup failure are preserved in the PR evidence; neither was hidden by an input retry. Background Cmd+V and direct AX value replacement remain open in #106. This is merged on main, not a claim about the currently installed Canary.

During native validation of #148, desktop_type on the Ace-dev ProseMirror Message AXTextArea returned: value write accepted but requested result could not be verified. A fresh pixel inspection confirmed the composer remained unchanged. No input replay or fallback injection was used; the effort menu itself was successfully exercised through AX clicks.

Another real `desktop_focus` timeout refusal, from the #156 pixel-authority model validation (signed Ace-dev `769438a`, disposable AppKit pointer fixture). Before a planned drag, pi/Anthropic called `desktop_windows`, then `desktop_focus` with the window's unchanged target. The call returned `refused` (`dispatch_state: none`, `refusal_reason: operation_unsupported`, `retry_safety: safe`) with message "Timeout while waiting for condition" and hint "Use a window and host that support focus window". The model stopped without dragging or retrying. In an earlier run the drag was not preceded by focus: it was accepted (`dispatched_unverified`) but recorded no fixture events, consistent with the documented inactive-view limit. The focus cause is not established here.

Observed again while native-verifying the queue UI for #24 in a signed source Ace-dev build (main 4d503d3 + queue changes). `desktop_inspect` exposed the Message AXTextArea as value-settable, but `desktop_type` returned unknown: "The accessibility value write was accepted, but its requested result could not be verified." A fresh pixel inspection showed the composer still contained only the Ace mention. I did not replay the input; used Ace CLI admissions for the real queued-message visual fixture instead.