fix(backup): terapkan restore DB saat startup (tunda swap) - menimpa DB di bawah koneksi hidup merusak (WAL)

config/database.js

@@ -10,6 +10,26 @@ if (!fs.existsSync(dbDir)) fs.mkdirSync(dbDir, { recursive: true });
 
 const dbPath = path.join(dbDir, 'billing.db');
 
+// Terapkan restore DB yang ditunda SEBELUM koneksi dibuka.
+// (menimpa billing.db di bawah koneksi hidup bisa merusak DB karena WAL bercampur)
+const _pendingRestore = path.join(dbDir, '.restore-pending');
+if (fs.existsSync(_pendingRestore)) {
+  try {
+    const _bkName = fs.readFileSync(_pendingRestore, 'utf8').trim();
+    const _bkPath = path.join(__dirname, '..', 'backups', _bkName);
+    if (_bkName && fs.existsSync(_bkPath)) {
+      fs.copyFileSync(_bkPath, dbPath);
+      for (const _ext of ['-wal', '-shm']) { try { fs.unlinkSync(dbPath + _ext); } catch (e) {} }
+      console.log('[DB] Restore tertunda diterapkan dari ' + _bkName);
+    } else {
+      console.error('[DB] Restore tertunda dilewati, backup tidak ada: ' + _bkName);
+    }
+  } catch (e) {
+    console.error('[DB] Gagal menerapkan restore tertunda:', e.message);
+  }
+  try { fs.unlinkSync(_pendingRestore); } catch (e) {}
+}
+
 let db;
 try {
   db = new Database(dbPath);

services/backupService.js

@@ -140,22 +140,19 @@ function restoreDatabase(backupFileName) {
       logger.warn('[Backup] Failed to create pre-restore backup');
     }
 
-    // Restore database
-    fs.copyFileSync(backupFilePath, dbPath);
-    // Buang WAL/SHM lama: backup VACUUM INTO self-contained, WAL lama milik DB sebelumnya
-    for (const ext of ['-wal', '-shm']) {
-      try { fs.unlinkSync(dbPath + ext); } catch (e) {}
-    }
+    // Tunda restore ke saat startup: menimpa DB di bawah koneksi hidup bisa merusak (WAL bercampur).
+    // Penanda dibaca config/database.js saat boot, sebelum koneksi dibuka.
+    const pendingPath = path.join(projectRoot, 'database', '.restore-pending');
+    fs.writeFileSync(pendingPath, backupFileName, 'utf8');
+    const size = fs.statSync(backupFilePath).size;
 
-    const stats = fs.statSync(dbPath);
-    const sizeKB = Math.round(stats.size / 1024);
-
-    logger.info(`[Backup] Database restored from: ${backupFileName} (${sizeKB} KB)`);
+    logger.info(`[Backup] Restore dijadwalkan (diterapkan saat restart): ${backupFileName}`);
 
     return {
       success: true,
       fileName: backupFileName,
-      size: stats.size,
+      size,
+      pendingRestart: true,
       timestamp: getNowLocalISO(),
       preRestoreBackup: preRestoreBackup.fileName
     };