修复节气计算/佛历倒计时/顶部固定高度+老黄历方框

- 节气改用精确查表(2000-2060天文算法生成)，修复立秋等大偏差
- 佛历倒计时/节日速查以当前选中日期为基准，切换日期实时更新
- 大日历顶部节日区/佛历区固定高度，空着也占位不再跳动
- 大日期加老黄历式方框（双线边框，节假日红/工作日绿）

mini/pages/home/home.js

@@ -82,6 +82,7 @@ Page({
     const almanac = getAlmanacInfo(y, m, d);
     this.setData({ dayInfo, almanac, currentYear: y, currentMonth: m });
     this.refreshDerived();
+    this.loadUpcoming();
   },
 
   /** 计算派生数据（节假日/工作日/佛历/初一十五） */
@@ -92,12 +93,14 @@ Page({
     const workday = isWorkday(y, m, d);
     const termTime = dayInfo.solarTerm ? (SOLAR_TERM_TIMES[dayInfo.solarTerm] || '') : '';
     const isFirstOrFifteen = highlightLunar && (dayInfo.lunarDay === 1 || dayInfo.lunarDay === 15);
-    const nextBuddhist = showBuddhist ? getNextBuddhistFestival() : null;
+    const nextBuddhist = showBuddhist ? getNextBuddhistFestival(y, m, d) : null;
     this.setData({ legalHoliday, workday, termTime, isFirstOrFifteen, nextBuddhist });
   },
 
   loadUpcoming() {
-    this.setData({ upcoming: getUpcomingFestivals(5) });
+    const { dayInfo } = this.data;
+    const { solarYear: y, solarMonth: m, solarDay: d } = dayInfo;
+    this.setData({ upcoming: getUpcomingFestivals(5, y, m, d) });
   },
 
   prevDay() { this.shiftDay(-1); },