supportsStatefulFlush

Whether the sync StreamingCompressor maintains compression state across flush() calls.

When true, calling StreamingCompressor.flush produces output that can be immediately decompressed, and the compressor can continue accepting more data for the same compression context.

When false, flush() produces independent compressed blocks and clears internal state.

• JVM, Android, Apple: true - true zlib z_stream maintains state

• JS (Node.js): false - sync API uses batch compression, state cleared after flush

• JS (Browser): false - CompressionStream doesn't support flush

Note: On JS Node.js, the async SuspendingStreamingCompressor DOES support stateful flush using the Transform stream API, even though this flag is false.