feat: implement native date pickers and YYYY-MM-DD format in Missing Data view

src/components/MissingDataView.tsx

@@ -14,20 +14,19 @@ interface MissingDataViewProps {
 
 function formatDateForInput(val: string): string {
   if (!val) return '';
+  // If it's already YYYY-MM-DD, return it
+  if (/^\d{4}-\d{2}-\d{2}$/.test(val)) return val;
+  // If it's DD/MM/YYYY, convert to YYYY-MM-DD
   const parts = val.split('/');
   if (parts.length === 3) {
-    return `${parts[2]}-${parts[1]}-${parts[0]}`;
+    return `${parts[2]}-${parts[1].padStart(2, '0')}-${parts[0].padStart(2, '0')}`;
   }
   return val;
 }
 
 function formatDateFromInput(val: string): string {
-  if (!val) return '';
-  const parts = val.split('-');
-  if (parts.length === 3) {
-    return `${parts[2]}/${parts[1]}/${parts[0]}`;
-  }
-  return val;
+  // Always output YYYY-MM-DD as requested
+  return val || '';
 }
 
 function formatDateValue(val: any): string {
@@ -36,11 +35,11 @@ function formatDateValue(val: any): string {
     if (val >= 25569 && val <= 60000) {
       const excelEpoch = new Date(1899, 11, 30);
       const date = new Date(excelEpoch.getTime() + val * 86400000);
-      return date.toLocaleDateString('en-GB', { day: '2-digit', month: '2-digit', year: 'numeric' });
+      return date.toISOString().split('T')[0]; // Returns YYYY-MM-DD
     }
     return '';
   }
-  return String(val);
+  return formatDateForInput(String(val));
 }
 
 function isEmptyOrEpoch(val: any): boolean {
@@ -160,12 +159,12 @@ export function MissingDataView({ data, headers, onSaveRow, onCaptureState }: Mi
       const colIdxNum = parseInt(colIdx);
       result = result.filter(r => {
         const val = r.row[colIdxNum];
-        const dateStr = formatDateValue(val) || String(val ?? '');
-        if (!dateStr) return false;
-        const parts = dateStr.split('/');
-        if (parts.length !== 3) return false;
-        const rowDate = new Date(`${parts[2]}-${parts[1]}-${parts[0]}`);
+        const dateStr = formatDateValue(val);
+        if (!dateStr || !/^\d{4}-\d{2}-\d{2}$/.test(dateStr)) return false;
+        
+        const rowDate = new Date(dateStr);
         if (isNaN(rowDate.getTime())) return false;
+        
         if (range.start) {
           const startDate = new Date(range.start);
           if (rowDate < startDate) return false;