//! IO pipelines.
//!
//! IO must be staged as parse -> builder -> finalization policy -> molecule.
//! Agents must not reintroduce parser code that mutates `Molecule` directly or
//! silently sanitizes/finalizes without an explicit policy.
//!
//! RDKit marker convention is defined in `dev/source_reproduction_protocol.md`.
//!
//! PDB/mmCIF policy:
//!
//! - `io::bio` is the Gemmi-aligned structural reader path into `BioStructure`.
//! - Future RDKit-compatible molecule input must be layered over `BioStructure`
//! conversion, not implemented as a second text parser.
//! - RDKit-derived PDB behavior belongs only to Molecule compatibility APIs.
//! - Do not expose parallel public parser modules for the same input format.
use crate::;