//! `chematic-core` — core cheminformatics types for the chematic ecosystem.
//!
//! Provides:
//! - [`Element`]: periodic-table element indexed by atomic number.
//! - [`Atom`]: a single atom with element, charge, isotope, aromaticity, chirality.
//! - [`BondOrder`] / [`BondEntry`]: bond types and graph edges.
//! - [`Molecule`] / [`MoleculeBuilder`]: undirected molecular graph (no external graph lib).
//! - [`implicit_hcount`]: valence-based implicit hydrogen count for organic-subset atoms.
//! - [`kekulize`] / [`apply_kekule`]: assign alternating single/double bonds to aromatic systems.
//!
//! # Design principles
//! - Pure Rust, no C/C++ FFI, no unsafe.
//! - Zero external dependencies: compiles to wasm32-unknown-unknown without modification.
//! - Domain-aware abstractions: graph types carry chemical semantics, not just topology.
// Re-export the most commonly used types at crate root.
pub use ;
pub use ;
pub use Element;
pub use ;
pub use ;
pub use ;