Home Assistant smart plug improvements:

- Add search parameter to /ha/entities endpoint for searching all entities
- Replace entity dropdown with searchable combobox (type to filter)
- Default shows switch/light/input_boolean; search queries all domains
- Make all three energy sensor dropdowns searchable (Power, Energy Today, Total)
- Each dropdown filters by entity_id or friendly_name
- Shows entity details (name, id, state, unit) in dropdown options

Fixes issue where HA plugs with non-standard entity naming couldn't
find their related power/energy sensors.

frontend/src/api/client.ts

@@ -2211,8 +2211,10 @@ export const api = {
       method: 'POST',
       body: JSON.stringify({ url, token }),
     }),
-  getHAEntities: () =>
-    request<HAEntity[]>('/smart-plugs/ha/entities'),
+  getHAEntities: (search?: string) => {
+    const params = search ? `?search=${encodeURIComponent(search)}` : '';
+    return request<HAEntity[]>(`/smart-plugs/ha/entities${params}`);
+  },
   getHASensorEntities: () =>
     request<HASensorEntity[]>('/smart-plugs/ha/sensors'),