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/**
 * FrodoKEM post-quantum key encapsulation integration.
 *
 * <p>
 * This package integrates the Frodo lattice-based key encapsulation mechanism
 * (KEM) into the core layer. It provides the algorithm descriptor, runtime KEM
 * context, key generation specifications, and encoded key specs for import and
 * export. Frodo is based on the hardness of the Learning With Errors (LWE)
 * problem, avoiding structured lattices and offering conservative security
 * margins.
 * </p>
 *
 * <h2>Scope and responsibilities</h2>
 * <ul>
 * <li>Register Frodo under a canonical identifier and declare
 * {@link zeroecho.core.KeyUsage#ENCAPSULATE} and
 * {@link zeroecho.core.KeyUsage#DECAPSULATE} roles, plus an agreement adapter
 * role for initiator/responder workflows.</li>
 * <li>Provide a {@link zeroecho.core.context.KemContext} implementation bound
 * to either a public or private key for encapsulation or decapsulation.</li>
 * <li>Expose immutable key-generation specifications and defensively copying
 * encoded-key carriers with marshalling helpers; private-key carriers are
 * destroyable.</li>
 * <li>Ensure operations are delegated to a supported PQC provider (BouncyCastle
 * PQC) and fail fast if absent.</li>
 * </ul>
 *
 * <h2>Components</h2>
 * <ul>
 * <li><b>FrodoAlgorithm:</b> algorithm descriptor that wires KEM and agreement
 * roles and registers key builders.</li>
 * <li><b>FrodoKemContext:</b> runtime context implementing encapsulate and
 * decapsulate operations using BouncyCastle’s Frodo engine.</li>
 * <li><b>FrodoKeyGenSpec:</b> immutable specification of the Frodo variant
 * (640, 976, 1344; AES or SHAKE-based), with convenience factories.</li>
 * <li><b>FrodoPublicKeySpec</b> / <b>FrodoPrivateKeySpec:</b> wrappers over
 * X.509 and PKCS#8 encodings with defensive copying and
 * {@link zeroecho.core.marshal.PairSeq} marshalling utilities.</li>
 * </ul>
 *
 * <h2>Design notes</h2>
 * <ul>
 * <li>Algorithm descriptors are immutable and safe to share across
 * threads.</li>
 * <li>KEM contexts are stateful and not thread-safe; they are intended for
 * single encapsulation or decapsulation operations.</li>
 * <li>Key specifications preserve encoded form without internal parsing and
 * rely on defensive cloning for safety.</li>
 * <li>Agreement adapters allow FrodoKEM to be composed into higher-level
 * initiator/responder protocols transparently.</li>
 * </ul>
 *
 * @since 1.0
 */
package zeroecho.core.alg.frodo;
