added recurrence (#35)

lib/types.ts

@@ -2,12 +2,14 @@ export type Habit = {
   id: string
   name: string
   description: string
-  frequency: 'daily' | 'weekly' | 'monthly'
+  frequency: string
   coinReward: number
   targetCompletions?: number // Optional field, default to 1
   completions: string[] // Array of UTC ISO date strings
 }
 
+export type Freq = 'daily' | 'weekly' | 'monthly' | 'yearly'
+
 export type WishlistItemType = {
   id: string
   name: string