fix(sidebar): unfreeze view after scan triggers history panel

forceView prop was overriding local activeView on every render. Once parent
set sidebarForceView='history' after starting a scan, it never cleared, so
clicks on other nav items were ignored. Treat forceView as a one-shot
trigger via the previous-prop pattern; user clicks afterward control view.

frontend/src/components/panels/Sidebar.tsx

@@ -43,13 +43,19 @@ interface SidebarProps {
 }
 
 export function Sidebar({ onAddNode, onAddGroupRect, onScan, onSave, onNodeApproved, forceView, highlightPendingId }: SidebarProps) {
-  const [_collapsed, setCollapsed] = useState(false)
-  const [_activeView, setActiveView] = useState<SidebarView>('canvas')
+  const [collapsed, setCollapsed] = useState(false)
+  const [activeView, setActiveView] = useState<SidebarView>(forceView ?? 'canvas')
+  const [prevForceView, setPrevForceView] = useState(forceView)
   const logout = useAuthStore((s) => s.logout)
 
-  // When forceView is set, override local state without useEffect
-  const collapsed = forceView ? false : _collapsed
-  const activeView = forceView ?? _activeView
+  // forceView acts as a one-shot trigger from parent; user clicks afterwards still control view.
+  if (forceView !== prevForceView) {
+    setPrevForceView(forceView)
+    if (forceView) {
+      setActiveView(forceView)
+      setCollapsed(false)
+    }
+  }
 
   const { nodes, hasUnsavedChanges, hideIp, toggleHideIp } = useCanvasStore()
 

frontend/src/components/panels/__tests__/Sidebar.test.tsx

@@ -267,6 +267,18 @@ describe('Sidebar', () => {
     await waitFor(() => expect(screen.getByText('No scans yet')).toBeInTheDocument())
   })
 
+  // Regression: forceView used to override local state on every render, freezing
+  // the sidebar on whichever view the parent forced (e.g. 'history' after a scan).
+  it('allows switching views after forceView is set by parent', async () => {
+    const { rerender } = render(<Sidebar {...defaultProps} forceView="history" />)
+    await waitFor(() => expect(screen.getByText('No scans yet')).toBeInTheDocument())
+    // Parent keeps forceView as 'history'; user clicks another nav item.
+    rerender(<Sidebar {...defaultProps} forceView="history" />)
+    fireEvent.click(screen.getByText('Pending Devices'))
+    await waitFor(() => expect(screen.getByText('No pending devices')).toBeInTheDocument())
+    expect(screen.queryByText('No scans yet')).not.toBeInTheDocument()
+  })
+
   it('toggles Settings panel on Settings click', async () => {
     render(<Sidebar {...defaultProps} />)
     fireEvent.click(screen.getByText('Settings'))