Function compress_block_zstd_dict 

pub fn compress_block_zstd_dict(
    data: &[u8],
    level: i32,
    dict: &[u8],
) -> Result<Vec<u8>>

Compress a block with a trained Zstd dictionary.

The output uses CODEC_TAG_ZSTD_DICT so the reader can route to decompress_block_zstd_dict with the segment’s stored dictionary.

Errors

Returns an error if the block exceeds MAX_BLOCK_SIZE.