feat(data): dedupe history by (date, employeeId)

js/data.js

@@ -61,11 +61,11 @@ export function toggleClosure(state, isoDate) {
   if (idx >= 0) arr.splice(idx, 1); else arr.push(isoDate);
 }
 
-// Adds entries to history, replacing any existing entries for the same dates
+// Adds entries to history, replacing any existing entries with the same (date, employeeId)
 export function addHistoryEntries(state, entries) {
   if (!entries?.length) return;
-  const dates = new Set(entries.map(e => e.date));
-  state.history = state.history.filter(h => !dates.has(h.date));
+  const keys = new Set(entries.map(e => e.date + '|' + e.employeeId));
+  state.history = state.history.filter(h => !keys.has(h.date + '|' + h.employeeId));
   state.history.push(...entries);
   state.history.sort((a, b) => a.date.localeCompare(b.date));
 }