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/**
 * HQC post-quantum key encapsulation integration.
 *
 * <p>
 * This package integrates the HQC (Hamming Quasi-Cyclic) KEM into the core
 * layer. It provides the algorithm descriptor, a runtime KEM context, and key
 * specifications for generation and import. Provider-specific details are
 * encapsulated behind small factories, while roles and metadata remain explicit
 * to higher layers.
 * </p>
 *
 * <h2>Scope and responsibilities</h2>
 * <ul>
 * <li>Register HQC under a canonical identifier and declare ENCAPSULATE and
 * DECAPSULATE roles, plus an agreement adapter for initiator and responder
 * workflows.</li>
 * <li>Provide a {@link zeroecho.core.context.KemContext} bound to a public or
 * private key for encapsulation or decapsulation.</li>
 * <li>Expose immutable key-generation specifications and defensively copying
 * encoded-key carriers with simple marshalling helpers; private-key carriers
 * are destroyable.</li>
 * <li>Ensure operations use a supported PQC provider and fail fast if the
 * provider is absent.</li>
 * </ul>
 *
 * <h2>Components</h2>
 * <ul>
 * <li><b>HqcAlgorithm</b>: algorithm descriptor wiring KEM and agreement roles
 * and registering key builders.</li>
 * <li><b>HqcKemContext</b>: runtime context implementing encapsulate and
 * decapsulate operations.</li>
 * <li><b>HqcKeyGenSpec</b>: specification of HQC variants (128, 192, 256) with
 * convenience factories.</li>
 * <li><b>HqcPublicKeySpec</b> and <b>HqcPrivateKeySpec</b>: wrappers over X.509
 * and PKCS#8 encodings, with defensive copying and compact 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; use one context per
 * operation.</li>
 * <li>Encoded key specs preserve the provided encodings without internal
 * parsing and clone byte arrays on input and output.</li>
 * <li>Agreement adapters allow HQC to be composed into message-based exchanges
 * where needed.</li>
 * </ul>
 *
 * @since 1.0
 */
package zeroecho.core.alg.hqc;
