[portal][fix] convert number to Month type

apps/portal/src/components/shared/MonthYearPicker.tsx

@@ -1,6 +1,6 @@
 import { Select } from '@tih/ui';
 
-type Month = 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12;
+export type Month = 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12;
 
 export type MonthYear = Readonly<{
   month: Month;

apps/portal/src/pages/index.tsx

@@ -3,14 +3,14 @@ import type { TypeaheadOption } from '@tih/ui';
 import { HorizontalDivider } from '@tih/ui';
 
 import CompaniesTypeahead from '~/components/shared/CompaniesTypeahead';
-import type { MonthYear } from '~/components/shared/MonthYearPicker';
+import type { Month, MonthYear } from '~/components/shared/MonthYearPicker';
 import MonthYearPicker from '~/components/shared/MonthYearPicker';
 
 export default function HomePage() {
   const [selectedCompany, setSelectedCompany] =
     useState<TypeaheadOption | null>(null);
   const [monthYear, setMonthYear] = useState<MonthYear>({
-    month: new Date().getMonth() + 1,
+    month: (new Date().getMonth() + 1) as Month,
     year: new Date().getFullYear(),
   });