feat(ui): extend set_clock_app to edit day/month/year, not just time

time_edit_field now cycles through 5 fields (hour/min/day/month/year)
via long-press CONFIRM. Up/down adjusts whichever field is focused,
with day clamped to Days_In_Month() when month/year changes, and
Clock_RecalcWeekday() called after every date edit so the weekday
label stays in sync. UI_UpdateSetTimeDigit() now also refreshes the
weekday abbreviation when editing day/month/year, since the computed
weekday can change independently of which digit was actually touched.
Save writes the full date+weekday via PCF8563_WriteDateTime(). Also
removes PCF8563_ReadTime()/WriteTime(), now unused since every caller
was updated to the DateTime variants directly.

App/ui.c

@@ -480,13 +480,14 @@ void UI_ShowSetTimePage(u8 hour, u8 min, u8 day, u8 month, u8 year, u8 weekday,
 
 /**
  * @brief 局部刷新时间设置界面里"正在调节的那一个"字段 (小时/分钟/日/月/年)
+ * @param weekday 根据当前日期算出的星期 (0=周日, ..., 6=周六)，调节日/月/年时顺带刷新星期缩写
  * @param selection 1:小时, 2:分钟, 3:日, 4:月, 5:年
  * @param blink_on 1:显示数值, 0:消隐(涂黑)，用于 500ms 周期闪烁效果
  * @details 小时/分钟用 32x32px 大字体区域；日/月/年用日期栏里对应的 16x16px 小字体区域，
  *          都只重画自己那一小块，不触碰锁头/电池/冒号/AM-PM/星期文字等其它内容，
  *          避免每次闪烁或调值都整屏 LCD_Clear() 造成全屏闪烁。
  */
-void UI_UpdateSetTimeDigit(u8 hour, u8 min, u8 day, u8 month, u8 year, u8 selection, u8 blink_on)
+void UI_UpdateSetTimeDigit(u8 hour, u8 min, u8 day, u8 month, u8 year, u8 weekday, u8 selection, u8 blink_on)
 {
     char buf[3];
     u16 x;
@@ -503,6 +504,12 @@ void UI_UpdateSetTimeDigit(u8 hour, u8 min, u8 day, u8 month, u8 year, u8 select
         default: x = DATE_BAR_YEAR_X; y = DATE_BAR_Y; w = DATE_BAR_FIELD_W; h = 16; value = year;  break;
     }
 
+    // 调节日/月/年时，星期缩写可能因为日期变化而改变，顺带刷新一下 (不参与闪烁，始终显示)
+    if (selection >= 3) {
+        LCD_FillRect(DATE_BAR_START_X, DATE_BAR_Y, 24, 16, COLOR_BLACK);
+        LCD_ShowString(DATE_BAR_START_X, DATE_BAR_Y, Lang_Get((StringID)(STR_WEEKDAY_SUN + weekday)), COLOR_GRAY, COLOR_BLACK);
+    }
+
     if (!blink_on) {
         // 灭周期：直接把这一小块涂黑，形成消隐效果
         LCD_FillRect(x, y, w, h, COLOR_BLACK);