Function compress_file 

pub fn compress_file(
    path: &Path,
    config: &EngineConfiguration,
) -> Result<Vec<u8>>

Compress a file at path using memory-mapped zero-copy I/O (FR-009).

This is the preferred entry point for large file inputs. Internally uses memmap2::MmapOptions to avoid copying file contents into a heap buffer before compression.

Errors

• CrushError::Io — file could not be opened or memory-mapped.
• CrushError::Cancelled — cancelled via the progress callback.
• CrushError::InvalidConfig — configuration validation failed.