fix: reset completed numeric habits from check button

frontend/src/MvpPanel.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { computed, nextTick, onBeforeUnmount, onMounted, ref } from 'vue'
 import { Activity, ArchiveRestore, Check, Download, FileJson, LogOut, RefreshCw, Trash2, Upload, X } from 'lucide-vue-next'
-import { dateKey, isHabitComplete, isHabitScheduledToday, mergePage, nextHabitSwipeValue, previousHabitSwipeValue, shouldToggleRowSwipe } from './lib/mvp-utils'
+import { dateKey, habitButtonValue, isHabitComplete, isHabitScheduledToday, mergePage, nextHabitSwipeValue, previousHabitSwipeValue, shouldToggleRowSwipe } from './lib/mvp-utils'
 import { csrfHeader } from './lib/csrf'
 
 type View = 'habits' | 'today-habits' | 'settings'
@@ -187,9 +187,7 @@ function cancelHabitSwipe(h?: Habit) {
 async function toggleHabitFromButton(h: Habit) {
   const current = logFor(h, todayKey.value)?.value
   const previous = current ?? 0
-  const next = isDone(h, todayKey.value)
-    ? previousHabitSwipeValue(h.kind, current)
-    : nextHabitSwipeValue(h.kind, current, h.target ?? 1)
+  const next = habitButtonValue(h.kind, current, h.target ?? 1)
   setLocalHabitValue(h, next)
   try {
     await request(`/habits/${h.id}/logs/${todayKey.value}`, { method: 'PUT', body: JSON.stringify({ value: next }) })

frontend/src/lib/mvp-utils.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { calendarModeLabel, clampFabPosition, countdownDayText, countdownKindLabel, dateKey, defaultView, habitWeek, isFabDrag, isHabitComplete, isHabitScheduledToday, isTaskView, nextHabitSwipeValue, numericHabitInputValue, previousHabitSwipeValue, quickTaskFields, shouldToggleRowSwipe } from './mvp-utils'
+import { calendarModeLabel, clampFabPosition, countdownDayText, countdownKindLabel, dateKey, defaultView, habitButtonValue, habitWeek, isFabDrag, isHabitComplete, isHabitScheduledToday, isTaskView, nextHabitSwipeValue, numericHabitInputValue, previousHabitSwipeValue, quickTaskFields, shouldToggleRowSwipe } from './mvp-utils'
 
 describe('MVP view utilities', () => {
   it('formats a local date as YYYY-MM-DD', () => {
@@ -63,6 +63,13 @@ describe('MVP view utilities', () => {
     expect(previousHabitSwipeValue('numeric', 0)).toBe(0)
   })
 
+  it('resets a completed numeric habit when its round button is clicked again', () => {
+    expect(habitButtonValue('numeric', 2, 3)).toBe(3)
+    expect(habitButtonValue('numeric', 3, 3)).toBe(0)
+    expect(habitButtonValue('boolean', 0, 1)).toBe(1)
+    expect(habitButtonValue('boolean', 1, 1)).toBe(0)
+  })
+
   it('renders countdown labels from date-only day values', () => {
     expect(countdownDayText(8)).toBe('还有 8 天')
     expect(countdownDayText(0)).toBe('就是今天')

frontend/src/lib/mvp-utils.ts

@@ -70,6 +70,11 @@ export function previousHabitSwipeValue(kind: string | undefined, current: numbe
   return 0
 }
 
+export function habitButtonValue(kind: string | undefined, current: number | boolean | undefined, target = 1) {
+  if (isHabitComplete(kind, current, target)) return 0
+  return nextHabitSwipeValue(kind, current, target)
+}
+
 export function numericHabitInputValue(input: number | string | undefined) {
   if (input === undefined || input === '') return null
   const value = Number(input)