# Scenario workspace — 2026-09-10

Owner: **Codex-9e8r6t /root/behavior_audit**. Root assigned the bounded layout slice after [the source audit](release-behavior-gap-audit-20260910.md). Scope is the scenario canvas, compact shelves, focus and independently scrollable form. Existing semantics, source grammar, REST commands and raw-draft recovery remain authoritative. No owner creation, missing-source creation, reuse semantics, state naming or commits/pushes are included.

## Coordination and current status

**Implementation in progress after integrated `057eddd` and F1 follow-up `a70de55`.** Root released the Rust source hold after palette_finish's integrated checkpoint compile, then assigned this worker the next sole Cargo lease after release_audit's metadata run. Codex-956atf's clicked-slot Action/Observation/Reuse/Fragment and caller-navigation work is integrated and retained; its separate lifetime projection remains owned on the other host in standalone `scenario_lifecycle.rs`. Root owns real native QA, integration and common ledgers/Wiki. No commits/pushes by this worker.

## Bounded implementation design

1. Integrate the other host's clicked-slot work first. Then move the existing scenario view/outline to `behavior/scenario/workspace.rs`, leaving its updated draft/planner/event semantics in `scenario.rs`. Keep the extracted fields/forms behavior unchanged before replacing its outer layout.
2. Use a compact stable header for owner, focus and shelf/camera actions. Tools and Selection are disclosures; place the existing sequence outline inside a scrolling shelf rather than beneath the diagram. Default shelves closed. Active-tool guidance is concise and always visible.
3. Keep a fixed widget-tree slot for the closed shelf (`Column::from_vec`; a zero-height child must not disappear). Allocate header and shelf once, then divide actual remaining height between the canvas and pending editor. Keep both canvas and form slots stable when the form opens/closes. Fields scroll independently; Create/Cancel remain outside the field scroller. No enclosing page scrollable.
4. Extend the existing process focus layout slot in `views.rs` to scenarios without moving the main workspace in the widget tree. Focus must retain selection, canvas state and raw draft. Coordinate any App change with root.
5. Evaluate measured viewport Fit/manual scale against actual Scene geometry. Existing Scene draws with `scale` and transforms pointer positions by that scale. If included, get viewport size from a sensor around the actual canvas scrollable, accept passive viewport changes under document/owner/revision guards, and invalidate old pointer epochs on geometry/scale changes. Use a readable default of 100%; tool changes must not force another scale. A Fit overview must be explicit, and limited overview scale must be disclosed. Do not infer available height from total window size.

## Planned verification

- Use the exact generic production pane builders with real Iced layout and scroll operations at minimum/wide center-pane sizes, with short/wrapped headers, open/closed shelves, pending forms and focused widths. Assert all canvas/action/field rectangles lie within the actual parent allocation; assert remaining space grows with the viewport.
- Establish real canvas/form scroll offsets, then diff across shelves, form open/cancel, focus and resize. Verify stable widget state and independent scrolling, not just widget counts. Full App tree-diff tests also preserve selected UUID, raw behavior recovery snapshot and the accepted document Arc.
- If camera controls are included, test default/manual/Fit against the scene bounds and measured viewport; finite inputs only; correct same-size notifications; stale context rejection; production click-click, drag and reorder at multiple scales with nonzero scroll origins.
- Retain existing scenario paired-call/branch/reorder/source/Undo/Redo/recovery tests. New geometry events remain passive during async saves and modal guards; drawing continues to reject pending source/properties/behavior edits.
- Root-owned native before/after task at 1440×900 and 1100×700: draw into a visible ALT operand, open a message/value form, scroll fields, reach Create/Cancel, open/close shelves and Focus, then Save/Undo/Redo/reopen. Actual Windows and Linux acceptance remain separate from unit/build results.

## Implemented slice

- Extracted the current scenario form/sequence outline into `behavior/scenario/workspace.rs`. Existing field choices, clicked slots, command planning, operation identity, correlation, raw recovery and ordered occurrence semantics remain in the original scenario module. Scene row/scope projection maps are unchanged for the separately owned lifetime renderer work.
- Replaced window-height subtraction/clamps and the enclosing page scroller with a permanent header/shelf/body tree. The canvas and form split the actual remaining height; opening/cancelling a form does not change the canvas tree path. Create/Cancel remain pinned above independently scrolling form fields. Tools and Selection are compact disclosures, the current tool remains visible, and Back to caller is reachable in the compact header.
- Added scenario presentation-only Focus, shelf and zoom events with exact context checks, plus passive measured viewport messages guarded by document/owner/revision. Default scale is 100%; explicit Fit uses the actual inner Scrollable with scrollbar allowance, with a disclosed 5% lower bound. Manual scale is retained across viewport changes. Nonfinite camera/scroll values are rejected.
- Caller navigation now retains scale/shelf/focus alongside both actual scroll offsets. The old Page scroll channel becomes the independent outline shelf; only the canvas channel contributes to canvas hit coordinates. Existing mounted observer restoration/receipt handling is retained, with a renderer-generic entry point for real Iced layout tests.
- Root's immutable integrated 618-test run independently exposed an existing Back failure after editing a caller reference. Diagnosed two related cases: a retarget edit can select a UUID outside the visible definition, and a rename can preselect the caller UUID so `select` skips restoring its active owner. The narrow Back handler now explicitly restores a valid caller's owner and normalizes a rejected Back's cross-owner selection to the still-visible definition. The existing test's source/history assertions are retained and its active-owner assertion is strengthened. The other host's independent [review #79](http://217.177.34.108:3000/sorokin.oleg.edu/ARCADIA-Studio/issues/1#issuecomment-79) identified the mirrored OpenUse preselection case; it now explicitly establishes the target owner. A dedicated mounted regression exercises both cases and their actual scroll restoration, tool/camera state, unchanged accepted Arc and history.
- Found and fixed an existing tool-selection inconsistency during the layout review: `CanvasEvent::Choose` called `App::apply`, which could commit a valid property draft when merely changing a drawing tool. Root authorized an explicit dirty-editor guard. The Tools shelf now disables its tool control and + Lifeline while source, property or behavior inputs are pending. An actual App-path regression covers valid and invalid drafts from all three editors, checking their validity and exact raw/accepted-state retention. Generic behavior Start handling remains a separately coordinated boundary for the new owner-creation work.

## Verification in progress

New `behavior/scenario/workspace/tests.rs` exercises the production pane builders with Iced's null renderer: minimum/wide geometry, pinned actions, canvas/form scroll retention across disclosures and resizing, mounted caller canvas/shelf restoration with camera state, measured Fit bounds and nonfinite rejection, passive/stale viewport events with raw drafts, full App tree identity, and scaled click-click/drag endpoints, root/ALT occurrences and reordering with nonzero scroll offsets.

The first focused compile reported an ambiguous `column!` import and an invariant Button lifetime introduced by extraction; both were corrected. The second compile passed six of seven tests, exposing an idle shelf allocation that left 282 px instead of the required 290 px canvas in the smallest, tallest-header case. Reducing the idle disclosure from 112 to 100 px resolved this without imposing a synthetic canvas-height clamp.

The third focused compile passed **8/8 workspace tests, 620 filtered**, after 5m27s compilation and 1.63s test execution. Across the full matrix, real Iced layout establishes at least 290 px idle canvas, 145 px pending canvas and 100 px pending form fields, with pinned actions. The tightest 500×570 / 132 px header / open-shelf allocation calculates to 294 px idle and 150 px pending canvas. These pane tests do not establish whole-window native acceptance. Logs/status: `.local/scenario-workspace-20260910/workspace-tests{,-2,-3}.log` and matching `-status.json`.

After root integrated the upstream explicit-enum F1 seed repair as `81668f9`, the complete scenario filter passed **52/52**, 579 filtered, in 29.60s after a 3m20s compile. This includes all ten new workspace tests and the unchanged original failing Back assertion with the added active-owner assertion. The history filter then passed **42/42**, 589 filtered, in 25.50s, including both formerly failing exhaustive/UUID-prose cases and the explicit-enum seed regression. Logs and exit-status JSON: `.local/scenario-workspace-20260910/{scenario-tests,history-tests}{.log,-status.json}`.

Root received an immutable **631-test** executable in `.local/scenario-workspace-20260910/tests-81668f9/arcadia-studio-tests.exe`, 104,007,680 bytes, SHA256 `FF5999466032E4FBDD615969E349720EC6B29A5945F7E3A57CCF976D8A2736E7`. The sibling `libunwind.dll` is 190,976 bytes, SHA256 `F45604A12E8BCD839FD86F667C1BE1CC7C4F9DA2B3C69FF381AC708F0E1AE7D4`. `manifest.json` records the source HEAD and 252 working-tree input hashes (including clearly marked present but undeclared creation modules), SHA256 `D06C72EBBE9B39A7CE2CCCFF888D2DE7892DFD07EA166FC308155642D37708EE`. Root owns the full run of this immutable artifact while this worker builds the GUI and performs fmt/strict Clippy under the coordinated source freeze.

Scoped rustfmt and diff checks pass. No current GUI binary or native acceptance is claimed at this checkpoint. Root's earlier immutable artifact had 615 passes and three failures; all three failing cases now pass the focused current gates above.