fix: all-day badge shows count for visible days only

Previously showed total allDayEvents.length (all events in the loaded
week). Now counts unique events that appear on at least one currently
visible day column, so in 1-day view it shows that day's count, in
3-day view the count across those 3 days, etc.

v1.81.12

package.json

@@ -1,6 +1,6 @@
 {
   "name": "my-weekly-todo-list",
-  "version": "1.81.11",
+  "version": "1.81.12",
   "description": "A web-based weekly task management application that organizes to-dos and calendar events in a single, intuitive weekly view",
   "main": "index.js",
   "scripts": {

src/components/WeeklyView.tsx

@@ -5239,7 +5239,12 @@ export default function WeeklyView() {
                                     marginTop: "1px",
                                 }}
                             >
-                                {allDayEvents.length}
+                                {(() => {
+                                    const visibleDays = getVisibleDays();
+                                    const seen = new Set<string>();
+                                    visibleDays.forEach(d => getAllDayEventsForDate(d).forEach(e => seen.add(e.id)));
+                                    return seen.size;
+                                })()}
                             </span>
                         </div>
                     )}