test: dedup sonner mocks and close Toolbar seam-mock gaps

- Replace 10 inline sonner toast mocks with the shared mockSonner() builder.
- Toolbar: add tests for the store-driven undo/redo disabled state and the
  unsaved-changes dot — behaviour the full-store mock previously left
  unasserted.

ha-relevant: yes

frontend/src/components/modals/__tests__/CustomStyleModal.test.tsx

@@ -4,7 +4,7 @@ import { CustomStyleModal } from '../CustomStyleModal'
 import { useThemeStore } from '@/stores/themeStore'
 import { useCanvasStore } from '@/stores/canvasStore'
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 import { toast } from 'sonner'
 
 describe('CustomStyleModal', () => {

frontend/src/components/modals/__tests__/PendingDevicesModal.test.tsx

@@ -31,7 +31,7 @@ vi.mock('@/api/client', () => ({
   },
 }))
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 
 vi.mock('@/components/modals/PendingDeviceModal', () => ({
   PendingDeviceModal: ({ device, onApprove }: { device: unknown; onApprove: (d: unknown) => void }) =>

frontend/src/components/modals/__tests__/ScanHistoryModal.test.tsx

@@ -3,7 +3,7 @@ import { render, screen, fireEvent, waitFor } from '@testing-library/react'
 import { ScanHistoryModal } from '../ScanHistoryModal'
 import { TooltipProvider } from '@/components/ui/tooltip'
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), warning: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 vi.mock('@/stores/canvasStore', () => ({
   useCanvasStore: { getState: () => ({ notifyScanDeviceFound: vi.fn() }) },
 }))

frontend/src/components/modals/__tests__/SettingsModal.test.tsx

@@ -2,7 +2,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest'
 import { render, screen, fireEvent, waitFor } from '@testing-library/react'
 import { SettingsModal } from '../SettingsModal'
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 vi.mock('@/api/client', () => ({
   settingsApi: {
     get: vi.fn(),

frontend/src/components/modals/__tests__/ThemeModal.test.tsx

@@ -5,7 +5,7 @@ import { useThemeStore } from '@/stores/themeStore'
 import { useCanvasStore } from '@/stores/canvasStore'
 import { THEME_ORDER } from '@/utils/themes'
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 import { toast } from 'sonner'
 
 describe('ThemeModal', () => {

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

@@ -24,7 +24,7 @@ vi.mock('@/api/client', () => ({
   },
 }))
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 
 vi.mock('@/components/ui/Logo', () => ({
   Logo: ({ showText }: { showText: boolean }) => (

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

@@ -61,6 +61,39 @@ describe('Toolbar', () => {
     render(<Toolbar {...defaultProps} />)
     expect(screen.getByText('View')).toBeInTheDocument()
   })
+
+  // These cover the store→UI wiring the seam mock would otherwise hide: the
+  // undo/redo disabled state and the unsaved dot are driven purely by store
+  // state, so assert them against the mocked slices.
+  it('disables Undo when the history stack is empty and Redo when the future is empty', () => {
+    mockStore({ past: [], future: [] })
+    render(<Toolbar {...defaultProps} />)
+    expect(screen.getByTitle('Undo (Ctrl+Z)')).toBeDisabled()
+    expect(screen.getByTitle('Redo (Ctrl+Y)')).toBeDisabled()
+  })
+
+  it('enables Undo/Redo when history/future have entries and forwards the clicks', () => {
+    mockStore({ past: [{}], future: [{}] } as Partial<ReturnType<typeof useCanvasStore>>)
+    render(<Toolbar {...defaultProps} />)
+    const undo = screen.getByTitle('Undo (Ctrl+Z)')
+    const redo = screen.getByTitle('Redo (Ctrl+Y)')
+    expect(undo).toBeEnabled()
+    expect(redo).toBeEnabled()
+    fireEvent.click(undo)
+    fireEvent.click(redo)
+    expect(defaultProps.onUndo).toHaveBeenCalledOnce()
+    expect(defaultProps.onRedo).toHaveBeenCalledOnce()
+  })
+
+  it('renders the unsaved-changes dot only when hasUnsavedChanges is true', () => {
+    const { rerender } = render(<Toolbar {...defaultProps} />)
+    // Save button is the last button; the dot is a sibling span with bg-[#e3b341].
+    expect(document.querySelector('.bg-\\[\\#e3b341\\]')).toBeNull()
+
+    mockStore({ hasUnsavedChanges: true })
+    rerender(<Toolbar {...defaultProps} />)
+    expect(document.querySelector('.bg-\\[\\#e3b341\\]')).not.toBeNull()
+  })
 })
 
 // ── Standalone mode ────────────────────────────────────────────────────────────

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

@@ -22,7 +22,7 @@ vi.mock('@/api/client', () => ({
   },
 }))
 
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 vi.mock('@/components/ui/Logo', () => ({ Logo: () => null }))
 vi.mock('@/components/ui/tooltip', () => ({
   Tooltip: ({ children }: { children: React.ReactNode }) => <>{children}</>,

frontend/src/components/proxmox/__tests__/ProxmoxImportModal.test.tsx

@@ -9,7 +9,7 @@ vi.mock('@/api/client', () => ({
     importToPending: vi.fn(),
   },
 }))
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 
 import { proxmoxApi } from '@/api/client'
 import { toast } from 'sonner'

frontend/src/components/zigbee/__tests__/ZigbeeImportModal.test.tsx

@@ -9,7 +9,7 @@ vi.mock('@/api/client', () => ({
     importToPending: vi.fn(),
   },
 }))
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 
 import { zigbeeApi } from '@/api/client'
 import { toast } from 'sonner'

frontend/src/components/zwave/__tests__/ZwaveImportModal.test.tsx

@@ -9,7 +9,7 @@ vi.mock('@/api/client', () => ({
     importToPending: vi.fn(),
   },
 }))
-vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn(), info: vi.fn() } }))
+vi.mock('sonner', async () => (await import('@/test/mocks')).mockSonner())
 
 import { zwaveApi } from '@/api/client'
 import { toast } from 'sonner'