Merge view controls and input orientation

Source pin: 7338078f8ddd924b8cddee35f512f2286072136d, MainFrm::OnViewSwitchleft, OnUpdateViewSwitchleft, the Toolbar/Status Bar commands in IDR_MAINFRAME, and the source toolbar/ribbon Switch artwork.

Two-file comparison now provides Switch left and right view in View and in the native toolbar customization palette. The source Save/Don't Save/Cancel workflow runs before exchanging inputs and reloading. Cancel retains drafts and orientation; accepted reload rebuilds differences, moves, annotations and Undo. The command also works in combined view and is disabled in single-file/image/ three-way contexts and while an operation, question or replacement owns the editor.

The exchange includes exact source bytes, encoding, source revisions, writable identity and Save As targets. Reload continues to use the exchanged orientation. Storage API calls retain original repository/working-file order; normal Save writes the displayed file, even when its writable side changes. Save As targets move with their source and continue to reload and save independently. No Git index/HEAD change is part of switching. The original Switch bitmap is copied unchanged and recorded in icon provenance.

Both editor families now expose saved Toolbar and Status Bar checkboxes. A hidden native toolbar retains its owner and customization without reintroducing the fallback command row. Native AppKit show/hide updates the same owning preference store. File/Open replacement installs the next owner with the saved visibility; retired toolbar items cannot act on it. Toolbar order/display-mode preferences remain independent of visibility. Status Bar hides the native bottom footer.

The two-pane split now owns its divider fraction in the supplied preference store. Combined view does not replace that fraction with its single-pane width. Returning to two panes and reopening a comparison restore it, with bounds for minimum pane widths. Resizing clamps the visible split without overwriting the user's preferred fraction. Divider tracking persists the accepted position; programmatic layout avoids redundant frame changes and writing to another preference domain.

Source Windows dock/ribbon layout and saved MFC workspace state are adapted to AppKit. Complete input-route, split-accessibility, physical gestures, all dialog visuals, minimum-OS and signed sandbox acceptance remain open.

Grouped evidence records three icon Core cases (two initially passed; the repaired bitmap registration/alpha case passed), the Debug build and all eight native case/engine runs. New view routing passed with system and bundled Git; retained toolbar, File/Open, moved-block, wrapped, two-pane and three-pane workflows passed. The new receiver had a missing engine argument and a native focus assumption corrected before that full pass. All owned receiver processes were reaped and independently absent. Final inspection added an explicit Switch refusal while the owner retains File/Open or is preparing its replacement. The affected view workflow then passed again with both Git engines, including held File/Open ownership without an attached sheet; the six unaffected retained workflows were not repeated.

Optional light/dark captures were inspected, but their toolbar icons look faded after the visibility/replacement sequence. They remain local QA candidates; physical toolbar appearance and its cause are unresolved. No new accepted gallery frame or complete Windows/editor/signed acceptance is claimed.

Hosted viewport readiness — October 16, 2026

Hosted run 38930685497 passed Git integration but timed out in the bundled-Git view receiver with a pending Base selection. Both engine cases passed locally before changing window hosting, so the exact hosted failure was not reproduced. The historical/repository and external-file comparison windows now explicitly order their native hosts with zero opacity, matching the first fixture window. Waiting for a native viewport no longer relies on an unshown window receiving incidental layout. All selection, exact Save/Save As/input routing, dirty Cancel, Undo, toolbar, split, replacement and Git-state assertions remain.

The shared wait reports the actual caller and each editor's attachment/geometry, initial navigation and pane mode if readiness still fails. This is an acceptance fixture correction, without a shipping UI or wait-budget change. A new passing hosted run is still required; local success cannot prove the timeout resolved.

Investigation evidence records both engine passes before and after explicit hosting, the diagnostic compile repair, and all four reaped receivers.