Reapply "added txt file export as extra export."

This reverts commit d51c16399c.

backend/managerRoutes.js

@@ -392,6 +392,7 @@ export default function () {
       }
 
       const wantXlsx = String(req.query.format || 'csv').toLowerCase() === 'xlsx'
+      const wantTxt = String(req.query.format || '').toLowerCase() === 'txt'
 
       let workerIdClause = ''
       let departmentClause = ''
@@ -522,6 +523,39 @@ export default function () {
         byWorkerForXlsx.set(`${w.username}||${w.full_name}||${w.department}`, perWorkerRows)
       }
 
+      // ===== TXT branch =====
+      if (wantTxt) {
+        const lines = []
+        for (const wId in workByDay) {
+          const w = workByDay[wId]
+          const seen = new Set()
+          for (const day of Object.keys(w.days).sort()) {
+            const events = w.days[day].slice().sort((a, b) => a.time - b.time)
+            for (const e of events) {
+              const code = e.type === 'clock_in' ? '1' : '0'
+              const date = ymdInTZ(e.time, TZ)
+              const timeStr = new Intl.DateTimeFormat('en-GB', {
+                timeZone: TZ,
+                hour: '2-digit',
+                minute: '2-digit',
+                second: '2-digit',
+                hour12: false,
+              }).format(e.time)
+              const line = `${w.username},"${code}","${date} ${timeStr}";"${w.full_name}"`
+              if (!seen.has(line)) {
+                seen.add(line)
+                lines.push(line)
+              }
+            }
+          }
+        }
+        res.set('X-Export-TZ', TZ)
+        res.header('Content-Type', 'text/plain')
+          .attachment(`attendance_${startDate}_to_${endDate}.txt`)
+          .send(lines.join('\n'))
+        return
+      }
+
       // ===== XLSX branch: grouped header + per-day summary sheet =====
       if (wantXlsx) {
         const wb = new ExcelJS.Workbook()