fix: read file size after streams are closed in converter

Tools/CacheConverter/Program.cs

@@ -102,15 +102,17 @@ await Parallel.ForEachAsync(jsonFiles, options, async (jsonFile, cancellationTok
             dataTable.Columns.Add(colName, colType);
         }
 
+        int rowCount = 0;
+        int batchCount = 0;
+
         // Stream JSON and write to protobuf in batches
+        // Use explicit dispose to ensure file is closed before reading size
+        {
             await using var inputFs = new FileStream(jsonFile, FileMode.Open, FileAccess.Read, FileShare.Read, 256 * 1024, FileOptions.SequentialScan | FileOptions.Asynchronous);
             await using var decompressStream = new DecompressionStream(inputFs);
             await using var outputFs = new FileStream(outputFile, FileMode.Create, FileAccess.Write, FileShare.None, 256 * 1024, FileOptions.Asynchronous);
             await using var compressStream = new CompressionStream(outputFs, level: 10);
 
-        int rowCount = 0;
-        int batchCount = 0;
-
             // True streaming: DeserializeAsyncEnumerable streams each array element without loading entire JSON
             var jsonOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
             await foreach (var element in JsonSerializer.DeserializeAsyncEnumerable<JsonElement>(
@@ -140,9 +142,9 @@ await Parallel.ForEachAsync(jsonFiles, options, async (jsonFile, cancellationTok
                 DataSerializer.Serialize(compressStream, reader);
                 batchCount++;
             }
+        } // Streams closed here
 
-        await compressStream.FlushAsync(cancellationToken);
-
+        // Read file size after streams are fully closed
         var newSize = new FileInfo(outputFile).Length;
         Interlocked.Add(ref totalNewSize, newSize);