Function encode_page_native 

pub fn encode_page_native(
    ty: TypeId,
    col: &NativeColumn,
    encoding: Encoding,
    compress: Compress,
    le: bool,
) -> Result<Vec<u8>>

Encode a typed column straight to an algo-prefixed page (no Value).

compress selects the on-disk algorithm (Phase 14.4 / 15.3): Plain emits raw ALGO_PLAIN (no compression — crate::Table::bulk_load_fast); Zstd(lvl) writes the zstd variants at lvl; Lz4 writes the LZ4 variants (hot runs, faster decode). Encoding::Plain forces raw plain regardless of compress.