fix: robust xlsx column parsing via header:'A'

Switched sheet_to_json from array (header:1) to column-letter objects
(header:'A'), so the parser reads B/C/D directly. Previous array
destructuring broke when the sheet's range did not start at column A.
Also added debug logging and a script-tag cache buster.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app.js

@@ -45,9 +45,12 @@ async function autoLoad() {
 
 function loadWorkbook(buf) {
   const wb = XLSX.read(buf, { type: 'array' });
+  console.log('[xlsx] sheets:', wb.SheetNames);
   const sheet = wb.SheetNames.find(n => n.toLowerCase().includes('функ')) || wb.SheetNames[0];
-  const rows = XLSX.utils.sheet_to_json(wb.Sheets[sheet], { header: 1, defval: null });
+  const rows = XLSX.utils.sheet_to_json(wb.Sheets[sheet], { header: 'A', defval: null });
+  console.log('[xlsx] rows:', rows.length, 'sample row 2:', rows[2]);
   state.items = parseRows(rows);
+  console.log('[xlsx] parsed items:', state.items.length);
   if (!state.items.length) return;
   populateGroups();
   showDashboard();
@@ -72,7 +75,9 @@ function parseRows(rows) {
   let group = 'Без группы';
   for (const row of rows) {
     if (!row) continue;
-    const [_, num, desc, time] = row;
+    const num = row.B;
+    const desc = row.C;
+    const time = row.D;
     if (!desc || String(desc).trim() === '' || String(desc).trim() === 'Функции:') continue;
     if (num == null || num === '') { group = String(desc).trim(); continue; }
     const n = Number(num);

index.html

@@ -61,6 +61,6 @@
 
   <p id="placeholder">Загрузка данных… Если дашборд не появился — нажмите «📁 Загрузить .xlsx».</p>
 
-  <script src="./app.js"></script>
+  <script src="./app.js?v=3"></script>
 </body>
 </html>