fix date type for ISODate

src/shared/types/date.ts

@@ -1,3 +1,5 @@
-export type ISODate = string
+type Brand<K, T> = K & { __brand: T }
 
-export const toISODate = (date: Date): ISODate => date.toISOString()
+export type ISODate = Brand<string, 'ISODate'>
+
+export const toISODate = (date: Date): ISODate => date.toISOString() as ISODate