refactor: ES6+ modernization + 2 bugfixes

- var→const/let, function→arrow/class across all 13 JS files
- Timer: prototype→class with ES6 getters
- plan days: IIFE→Array.from declarative generation
- storage/plan: unified formatDate via util.js
- Bugfix: getPlanDay now filters by planId (plan switch accuracy)
- Bugfix: getTodayRecord searches all months (cross-month boundary)
- WXML/WXSS unchanged; public API unchanged

pages/settings/settings.js

@@ -1,5 +1,5 @@
-var storage = require('../../utils/storage')
-var themeMod = require('../../utils/theme')
+const storage = require('../../utils/storage')
+const themeMod = require('../../utils/theme')
 
 Page({
   data: {
@@ -19,9 +19,9 @@ Page({
     vibrate: true
   },
 
-  onLoad: function () {
-    var s = storage.getSettings()
-    var theme = themeMod.getCurrentTheme()
+  onLoad() {
+    const s = storage.getSettings()
+    const theme = themeMod.getCurrentTheme()
     themeMod.applyThemeToPage(this)
     this.setData({
       currentPlanId: s.planId,
@@ -33,70 +33,68 @@ Page({
     })
   },
 
-  onShow: function () {
+  onShow() {
     try {
-      var tb = this.getTabBar()
+      const tb = this.getTabBar()
       if (tb) tb.setData({ selected: 2 })
     } catch (e) {}
     themeMod.applyThemeToPage(this)
   },
 
-  onSelectTheme: function (e) {
-    var id = e.currentTarget.dataset.id
-    var theme = themeMod.setTheme(id)
+  onSelectTheme(e) {
+    const id = e.currentTarget.dataset.id
+    const theme = themeMod.setTheme(id)
     this.setData({ currentThemeId: id })
 
     try {
-      var tb = this.getTabBar()
-      if (tb) {
-        tb.setData({ themeStyle: themeMod.getThemeStyle(theme) })
-      }
+      const tb = this.getTabBar()
+      if (tb) tb.setData({ themeStyle: themeMod.getThemeStyle(theme) })
     } catch (e) {}
 
     themeMod.applyThemeToPage(this)
   },
 
-  onSelectPlan: function (e) {
-    var planId = e.currentTarget.dataset.id
-    var s = storage.getSettings()
+  onSelectPlan(e) {
+    const planId = e.currentTarget.dataset.id
+    const s = storage.getSettings()
     s.planId = planId
     storage.saveSettings(s)
     this.setData({ currentPlanId: planId })
     wx.showToast({ title: '计划已切换', icon: 'success', duration: 1200 })
   },
 
-  onToggleReminder: function (e) {
-    var s = storage.getSettings()
+  onToggleReminder(e) {
+    const s = storage.getSettings()
     s.dailyReminder = e.detail.value
     storage.saveSettings(s)
     this.setData({ dailyReminder: e.detail.value })
   },
 
-  onReminderTimeChange: function (e) {
-    var s = storage.getSettings()
+  onReminderTimeChange(e) {
+    const s = storage.getSettings()
     s.reminderTime = e.detail.value
     storage.saveSettings(s)
     this.setData({ reminderTime: e.detail.value })
   },
 
-  onToggleVoice: function (e) {
-    var s = storage.getSettings()
+  onToggleVoice(e) {
+    const s = storage.getSettings()
     s.voiceGuide = e.detail.value
     storage.saveSettings(s)
     this.setData({ voiceGuide: e.detail.value })
   },
 
-  onToggleVibrate: function (e) {
-    var s = storage.getSettings()
+  onToggleVibrate(e) {
+    const s = storage.getSettings()
     s.vibrate = e.detail.value
     storage.saveSettings(s)
     this.setData({ vibrate: e.detail.value })
   },
 
-  onCopyWechat: function () {
+  onCopyWechat() {
     wx.setClipboardData({
       data: '刘承',
-      success: function () {
+      success: () => {
         wx.showToast({ title: '已复制', icon: 'success', duration: 1500 })
       }
     })