fix: SW-2054 correct DataAppShell Storybook E2E test assertions for icon-only rail (#155)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Oseer Williams (Small Fry) <265368733+owilliams-tetrascience@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/components/composed/DataAppShell/DataAppShell.stories.tsx

@@ -127,8 +127,6 @@ interface WorkflowStep {
   isActive?: boolean;
   disabled?: boolean;
   disabledReason?: string;
-  inputCount?: number;
-  outputCount?: number;
   onClick?: () => void;
 }
 
@@ -346,7 +344,7 @@ const DefaultShell = ({ initialCollapsed = false }: { initialCollapsed?: boolean
             <Button
               variant="outline"
               size="sm"
-              onClick={() => setActiveStepId(htsWorkflowSteps[activeStepIndex - 1].id)}
+              onClick={() => setActiveStepId(steps[activeStepIndex - 1].id)}
               className="gap-1"
             >
               Back
@@ -715,17 +713,13 @@ const WorkflowInteractionShell = () => {
       icon: LayoutGrid,
       isActive: activeStepId === "step-a",
       onClick: () => setActiveStepId("step-a"),
-      inputCount: 1000,
-      outputCount: 800,
     },
     {
       id: "step-b",
       label: "Step Beta",
       icon: Filter,
       isActive: activeStepId === "step-b",
       onClick: () => setActiveStepId("step-b"),
-      inputCount: 800,
-      outputCount: 200,
     },
     { id: "step-c", label: "Disabled", icon: Search, disabled: true, disabledReason: "Requires upstream data" },
   ];

src/components/composed/DataAppShell/DataAppShell.tsx

@@ -174,8 +174,6 @@ function SidebarBody({
       <div
         className={cn(
           "shrink-0 flex",
-          // Expanded: full-width header border. Collapsed: no full-width border —
-          // a short centered divider (below) aligns under the icon column instead.
           compact ? "justify-center pt-1 pb-2" : "px-3 py-2.5 border-b border-sidebar-border"
         )}
       >