fix(database): enable SQLite WAL before schema reconciliation

JobTrackerApi.Tests/DatabaseBackupRunnerTests.cs

@@ -54,6 +54,39 @@ public sealed class DatabaseBackupRunnerTests : IDisposable
         Assert.Equal(2L, (long)(await count.ExecuteScalarAsync())!);
     }
 
+    [Fact]
+    public async Task RunOnce_includes_committed_WAL_rows_in_an_independent_restorable_snapshot()
+    {
+        CreateSourceDb(out var connectionString);
+        await using var source = new SqliteConnection(connectionString);
+        await source.OpenAsync();
+        await using var write = source.CreateCommand();
+        write.CommandText = "PRAGMA journal_mode=WAL;";
+        Assert.Equal("wal", await write.ExecuteScalarAsync());
+        write.CommandText = "INSERT INTO Sample (Name) VALUES ('committed-in-wal');";
+        await write.ExecuteNonQueryAsync();
+        Assert.True(new FileInfo(Path.Combine(_root, "source.db-wal")).Length > 0);
+
+        var backupPath = await CreateRunner(connectionString).RunOnceAsync(CancellationToken.None);
+        Assert.NotNull(backupPath);
+        await using var backup = new SqliteConnection($"Data Source={backupPath};Mode=ReadOnly;Pooling=False");
+        await backup.OpenAsync();
+        await using var query = backup.CreateCommand();
+        query.CommandText = "PRAGMA integrity_check;";
+        Assert.Equal("ok", await query.ExecuteScalarAsync());
+        query.CommandText = "SELECT COUNT(*) FROM Sample;";
+        Assert.Equal(3L, await query.ExecuteScalarAsync());
+        query.CommandText = "SELECT Name FROM Sample WHERE Id=3;";
+        Assert.Equal("committed-in-wal", await query.ExecuteScalarAsync());
+
+        write.CommandText = "INSERT INTO Sample (Name) VALUES ('after-snapshot');";
+        await write.ExecuteNonQueryAsync();
+        query.CommandText = "SELECT COUNT(*) FROM Sample;";
+        Assert.Equal(3L, await query.ExecuteScalarAsync());
+        write.CommandText = "SELECT COUNT(*) FROM Sample;";
+        Assert.Equal(4L, await write.ExecuteScalarAsync());
+    }
+
     [Fact]
     public async Task RunOnce_prunes_backups_beyond_retention()
     {