Further performance improvements

Further removed multiple pointer instances
Re-use decompression readers (except zstd due to bugs)

internal/decompress/zstd.go

@@ -1,19 +1,16 @@
 package decompress
 
 import (
-	"bytes"
-	"io"
-
 	"github.com/klauspost/compress/zstd"
 )
 
 type Zstd struct{}
 
 func (z Zstd) Decompress(data []byte) ([]byte, error) {
-	rdr, err := zstd.NewReader(bytes.NewReader(data))
+	rdr, err := zstd.NewReader(nil, zstd.WithDecoderLowmem(true), zstd.WithDecoderConcurrency(1))
 	if err != nil {
 		return nil, err
 	}
 	defer rdr.Close()
-	return io.ReadAll(rdr)
+	return rdr.DecodeAll(data, nil)
 }