feat: birthday tracking, dashboard KPIs, and app name customization (#88)

- Add Birthdays module: CRUD with calendar/reminder auto-sync, photo upload, age notes
- Add DB migration 18 (birthdays table with calendar_event_id, trigger, indexes)
- Add dashboard widgets: birthdays, family participants, budget overview
- Add Settings > General: admins can set a custom app name (reflected in title/sidebar/login)
- Improve service worker: network-first caching for mutable JS/CSS assets
- Add translations for 16 locales (birthday keys)

Fixes applied during integration:
- innerHTML replaced with insertAdjacentHTML/replaceChildren throughout birthdays.js and dashboard.js
- docker-compose.yml personal dev changes reverted

Co-authored-by: Rafael Foster <rafaelgfoster@gmail.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/locales/zh.json

@@ -38,6 +38,7 @@
     "shopping": "购物",
     "notes": "便签",
     "contacts": "联系人",
+    "birthdays": "生日",
     "budget": "预算",
     "settings": "设置",
     "main": "主导航",
@@ -82,6 +83,19 @@
     "allDay": "全天",
     "shoppingMore": "+{{count}} 更多",
     "weather": "天气",
+    "familyMembers": "家庭成员",
+    "participantsAdded": "位参与者已添加",
+    "upcomingBirthdays": "即将到来的生日",
+    "noBirthdays": "还没有生日",
+    "daysLeft": "{{count}} 天",
+    "budgetOverview": "预算概览",
+    "monthlyIncome": "收入",
+    "monthlyExpenses": "支出",
+    "monthlyBalance": "余额",
+    "savingsRate": "储蓄率",
+    "topExpense": "最大支出",
+    "budgetEntries": "记录",
+    "noBudgetData": "本月没有预算数据。",
     "customize": "自定义",
     "customizeTitle": "自定义小组件",
     "customizeReset": "重置",
@@ -537,6 +551,7 @@
     "tabAccount": "账户",
     "tabsAriaLabel": "设置类别",
     "sectionDesign": "外观",
+    "sectionAppName": "应用名称",
     "sectionShopping": "购物",
     "shoppingCategoriesLabel": "购物分类",
     "shoppingCategoriesHint": "添加、重命名、删除或排序分类。",
@@ -554,6 +569,16 @@
     "sectionCalendarSync": "日历同步",
     "sectionFamily": "家庭成员",
     "cardAppearance": "外观",
+    "appNameTitle": "应用名称",
+    "appNameLabel": "应用名称",
+    "appNameHint": "此名称会显示在侧边栏、浏览器标题和登录界面中。",
+    "appNamePlaceholder": "Oikos",
+    "appNameSavedToast": "应用名称已保存。",
+    "sectionDate": "日期",
+    "dateFormatTitle": "日期格式",
+    "dateFormatLabel": "首选日期格式",
+    "dateFormatHint": "选择日期在应用中的显示方式。",
+    "dateFormatSavedToast": "日期格式已保存。",
     "themeSystem": "跟随系统",
     "themeSysLabel": "使用系统设置",
     "themeLight": "浅色",
@@ -760,6 +785,34 @@
     "placeholder": "搜索…",
     "noResults": "未找到结果。"
   },
+  "birthdays": {
+    "title": "生日",
+    "addButton": "添加生日",
+    "searchPlaceholder": "搜索生日…",
+    "upcomingTitle": "即将到来的生日",
+    "upcomingHint": "接下来的生日庆祝，已同步到日历。",
+    "peopleTitle": "人物",
+    "peopleHint": "搜索、查看并编辑所有已保存的生日。",
+    "emptyTitle": "还没有生日",
+    "emptyDescription": "添加一个生日，让它显示在日历和提醒中。",
+    "newTitle": "新建生日",
+    "editTitle": "编辑生日",
+    "nameLabel": "姓名",
+    "birthDateLabel": "出生日期",
+    "photoLabel": "头像",
+    "removePhoto": "删除照片",
+    "notesLabel": "备注",
+    "notesPlaceholder": "礼物想法、最喜欢的蛋糕、家庭备注…",
+    "calendarHint": "每个生日都会自动添加到日历和提醒系统中。",
+    "requiredFields": "姓名和出生日期为必填项。",
+    "createdToast": "生日已保存。",
+    "updatedToast": "生日已更新。",
+    "deletedToast": "生日已删除。",
+    "deleteConfirm": "删除“{{name}}”的生日？",
+    "ageNoteToday": "今天满 {{age}} 岁。",
+    "ageNoteTomorrow": "明天满 {{age}} 岁。",
+    "ageNoteDays": "{{days}} 天后满 {{age}} 岁。"
+  },
   "reminders": {
     "sectionTitle": "提醒",
     "enableLabel": "设置提醒",