M8-T18: add source and multi-commodity meter UI

frontend/src/energy/hooks.test.tsx

@@ -81,6 +81,7 @@ function makeWrapper() {
 // ---------------------------------------------------------------------------
 
 describe('useDevices', () => {
+  // Source hooks use the same typed client and QueryClient invalidation boundary.
   beforeEach(() => vi.clearAllMocks())
 
   it('calls GET /api/modbus/devices and returns device list', async () => {
@@ -98,6 +99,24 @@ describe('useDevices', () => {
   })
 })
 
+describe('useDeclareMeter source binding invalidation', () => {
+  beforeEach(() => vi.clearAllMocks())
+  it('invalidates every cache affected by atomic meter and binding creation', async () => {
+    mockPost.mockResolvedValue({ data: { id: 9 } })
+    const { qc, Wrapper } = makeWrapper()
+    const affectedKeys = [
+      ['energy-meters'], ['energy-source-channels'], ['energy-meter-bindings', 9],
+      ['energy-sources'], ['expose-catalog'], ['energy-costs'], ['energy-costs-summary'],
+    ]
+    for (const queryKey of affectedKeys) qc.setQueryData(queryKey, { cached: true })
+    const { useDeclareMeter } = await import('./hooks')
+    const { result } = renderHook(() => useDeclareMeter(), { wrapper: Wrapper })
+    await act(async () => { await result.current.mutateAsync({ label: 'Heat', commodity: 'heating', started_at: '2026-08-01T00:00:00Z', reason: 'initial', source_channel_uuid: 'channel-1' } as never) })
+    expect(mockPost).toHaveBeenCalledWith('/api/energy/meters', expect.objectContaining({ body: expect.objectContaining({ source_channel_uuid: 'channel-1' }) }))
+    for (const queryKey of affectedKeys) expect(qc.getQueryState(queryKey)?.isInvalidated).toBe(true)
+  })
+})
+
 describe('useProfiles', () => {
   beforeEach(() => vi.clearAllMocks())