fix: disallow selecting dates in the past or today

datetime.js

@@ -50,7 +50,7 @@
 
       const upcoming = Array.from(availableDatesMap.keys())
         .map((dateKey) => new Date(`${dateKey}T00:00:00`))
-        .filter((date) => date >= today)
+        .filter((date) => date > today)
         .sort((a, b) => a - b);
 
       if (upcoming.length > 0) {
@@ -88,7 +88,8 @@
       button.textContent = String(day);
 
       const dateInfo = availableDatesMap.get(key);
-      const isAvailable = Boolean(dateInfo);
+      const isPastOrToday = cellDate <= today;
+      const isAvailable = Boolean(dateInfo) && !isPastOrToday;
       const isToday = cellDate.getTime() === today.getTime();
       const isSelected = selectedDate && cellDate.getTime() === selectedDate.getTime();