refactor(mini): 个人中心改为登录+二级菜单结构

- 个人中心仅保留登录管理、我的数据/功能菜单与关于信息
- 新增偏好设置二级页 preferences（原偏好设置统一收敛至此）
- 新增我的收藏二级页 bookmarks，支持删除与跳转日详情
- 生辰管理拆分为二级页 birth-profiles，未登录时提示引导登录
- 八字页入口改为直达生辰管理页；修复 fortune 非 tabBar 页误用 switchTab

mini/pages/preferences/preferences.js

@@ -0,0 +1,54 @@
+Page({
+  data: {
+    weekStartDay: 0,
+    ziHourSect: 'lateZiNextDay',
+    solarTime: true,
+    showBuddhist: false,
+    highlightLunar: true
+  },
+
+  onShow() {
+    this.loadSettings();
+  },
+
+  loadSettings() {
+    const settings = wx.getStorageSync('lunar-settings') || {};
+    this.setData({
+      weekStartDay: settings.weekStartDay || 0,
+      ziHourSect: settings.ziHourSect || 'lateZiNextDay',
+      solarTime: settings.solarTime !== false,
+      showBuddhist: settings.showBuddhist === true,
+      highlightLunar: settings.highlightLunar !== false
+    });
+  },
+
+  saveSettings() {
+    const { weekStartDay, ziHourSect, solarTime, showBuddhist, highlightLunar } = this.data;
+    wx.setStorageSync('lunar-settings', { weekStartDay, ziHourSect, solarTime, showBuddhist, highlightLunar });
+  },
+
+  setWeekStart(e) {
+    this.setData({ weekStartDay: Number(e.currentTarget.dataset.v) });
+    this.saveSettings();
+  },
+
+  setZiSect(e) {
+    this.setData({ ziHourSect: e.currentTarget.dataset.v });
+    this.saveSettings();
+  },
+
+  onSolarTimeChange(e) {
+    this.setData({ solarTime: e.detail.value });
+    this.saveSettings();
+  },
+
+  onBuddhistChange(e) {
+    this.setData({ showBuddhist: e.detail.value });
+    this.saveSettings();
+  },
+
+  onHighlightLunarChange(e) {
+    this.setData({ highlightLunar: e.detail.value });
+    this.saveSettings();
+  }
+});