Workspace shell [UI]

The regions of WorkspaceShell — a stable cockpit around a mutable Stage. Two edge rails share the same RailFrame chrome and each toggle a collapsible pane beside them.

flowchart TB
    TopBar["**TopBar** — menus · theme · usage · audio · export · slides"]
    TopBar --> Rail & SideL & StageBar & URail

    Rail["**DomainRail** (left, 56px)<br/>story tiles"]
    SideL["**DrivePanel** (left pane)<br/>the Drive"]
    URail["**UtilityRail** (right, 56px)<br/>panel tabs"]
    URail -->|opens active tab| UPanel["**UtilityPanel** (right pane)"]

    StageBar["**StageBar** — view switcher"] -->|sets state.stageView| Stage["**Stage** — render dispatch"]
    Stage --> Palette["StagePalette (overlay)"]
    StageBar --> RunBar["**RunBar** — run status"] --> Bottom["ScenePanel · TimelineStrip · ForceTimeline"]

• DomainRail (left, story tiles) toggles DrivePanel (the Drive); UtilityRail (right, panel tabs) toggles UtilityPanel (the popout). (This rail + popout split replaced the former single InspectorPanel; tab state lives in inspector/utility-panel-context.)
• The center is a render switch on state.stageView — the views it dispatches to are in ui/center-views; the right popout's tabs in ui/inspector; the TopBar menus in ui/topbar.
• On a phone this whole shell is replaced by a separate focused path — ui/mobile.