# Scenario authoring: native Windows evidence, 2026-09-11

Codex-956atf `/root`. This is a partial capability checkpoint, not first-release
acceptance. Actual Studio was operated through the Computer Use `sky` API against
copies of the independently generated [fixture](fixtures/scenario-authoring/README.md).
No fixture fields or expected transactions were changed to match the observed UI.

## Build and execution identity

- Rust implementation: `80cf197be6f1d400bf0b9c84bf8557f88c895aa6`.
- `cargo build --locked -p oa-desktop --bin arcadia-studio`: exit0, 3m28s,
  warning-free dev build. Log `.local/logs/desktop-gui-integrated-20260911.log`.
- Executable SHA256: `A5ED6DF334B1BFB620425AFDF3E863F0B522990E6FB47C6C401A71CF4443954A`.
- Immutable native staging directory: `.local/native-qa/studio-80cf197/`.
- Bundled `libunwind.dll` SHA256:
  `AA282FA47BB2C4E210CEA5E470CDBDCA58568F0BE0BC73E404D86AB9CD95EF6A`.
- Process4416 opened the real Iced workspace. The launch helper initially reported
  no targetable window; a fresh window listing found the completed workspace.
  No second instance was launched. The debug console window was not automated.
- Full desktop tests passed642/642 before this native run. Their executable/hash
  differ from the GUI; see [STATE](STATE.md). Formatting passed. Subsequent strict
  Clippy found two collapsible-if statements, corrected after this immutable build;
  the current lint gate is not yet claimed passing.

The native checker requires the task-local runtime on PATH; an initial invocation
without the toolchain environment exited `-1073741515`. Sourcing
`.local/toolchain/env.ps1` resolved that launch dependency. Both new OA/SA working
copies then passed the baseline checker. This was a checker-launch error, not a
semantic fixture failure. The GUI stage includes its runtime beside the executable.

## Observed navigation and layout

Opened `.local/native-qa/scenario-20260911/oa/project.arcadia` through Studio's
normal Open dialog. The initial window captured1442×932 pixels, corresponding to
the1440×900 client. The project contains62 elements, zero relations and11 fixture
engineering warnings; that matches the independently constructed baseline.

At normal size, selected OA A caller and Behavior & scenarios. The new workspace
keeps the scenario selector and compact controls above the remaining-height canvas.
Fit displayed the whole nested caller at42%; opening Selection reduced available
height and recomputed35%. These overview scales are for navigation, not readable
detailed editing of every nested label.

1. Selected **OA Second use of B**, verified its name and alias
   `scenario_oa_61`, then Selection → Open definition. The canvas changed to
   **OA B verification** with Back to caller available.
2. Selected **OA B use of C** (`scenario_oa_64`), opened C, then Back twice.
   First return restored B's exact use; second restored A's **Second use of B**,
   its Selection panel and35% overview. The initiating use was not replaced by the
   similarly targeted first use.
3. Repeated A→B→A through **OA First use of B** (`scenario_oa_60`). Return selected
   that first occurrence and preserved its presentation.
4. Switched A to100%, scrolled the actual canvas until the two reuse blocks were
   visible, opened B and returned. The first-use block returned to the same visible
   y-position (top646, label666 in the captured window) and remained selected.
   A subsequent upward scroll moved naturally; Save did not snap it back.
5. Save all completed. Independent `check baseline` passed the whole Project and
   both reachable source files, including the retained note. Navigation introduced
   no accepted source/model difference in this checkpoint.

Resized through the Windows system-menu Size command, using Right/Down then a
pointer placement. The resulting capture was1102×732 pixels:1100×700 client, the
application's configured minimum. The initial corner drag did not resize; it is
not counted as a sizing result. At minimum size, Fit recomputed21% with Selection
open and28% after closing Selection. Focus canvas hid the side panels and Restore
panels remained accessible. Normal-scale editing retained a real scrollable canvas.

## OA action: creation and exact history pass

Performed the fixture's prescribed `oa-action` task at the minimum1100×700 client,
with focused canvas and100% scale. Tools → Add action exposed an explicit root
insertion line labeled before **OA Root entry**. Clicked that line at the
**OA A inspector** lifeline, not the Tools append action.

The pending marker retained the chosen owner/before-slot/lifeline. The bottom form
kept **Create** and **Cancel** pinned while its fields scrolled independently.
Entered literal name **OA native action**, selected work **OA Inspect ticket**,
and confirmed the preselected observed lifeline **OA A inspector**. Create added
one action before Root entry; the canvas showed63 objects and selected the new
action. Save all completed.

| Native stage | Independent result | Preserved whole-directory snapshot |
| --- | --- | --- |
| Before Create | Previously checked baseline | `.local/native-qa/scenario-20260911/oa-baseline-verified/` |
| Create, Save | `check oa-action` PASS | `oa-action-verified/` under the same run directory |
| Ctrl+Z, Save | `check baseline` PASS; `same baseline-verified working` PASS | `oa-action-undo/` |
| Ctrl+Y, Save | `check oa-action` PASS; `same action-verified working` PASS | `oa-action-redo/` |

Every `same` comparison covers all Project identities/fields and every SourceBundle
byte. The semantic checker borrows only the unique fresh role UUID and independently
predicts the remaining graph. The verified snapshots were preserved before Undo;
restored snapshots did not replace them. All checker commands exited0. Tool outputs
record both semantic and exact equality passes.

## Open native gates

OA nested state observation/reuse/fragment and all four SA creation checkpoints,
final reopen, blocked navigation/cancellation/recovery, detailed-list definition
entry, minimum-size nested caller return, and B4 lifecycle rendering remain open.
This report does not infer them from the passing root action. B4 is still a pure
cfg(test) projection; independent Scene review identified lifetime bounds,
branch-local activation clipping, incomplete-lane geometry and self-arrow endpoint
work before production integration.

Continue from the saved OA action state in the run directory, following the exact
fixture procedure. Root retains native input; concurrent source builds use the
separate target tree and must not overwrite the running staged executable.