The `KeyBag` class provides a generic, fingerprint-based cryptographic key storage abstraction. It supports multiple provider implementations (memory, file, IndexedDB) and enables key lookup by fingerprint, key import/export, and key migration between versions. This module is isolated with minimal internal dependencies and could be extracted as a standalone key management library for any application requiring secure key storage with flexible backends.

Implements a local Certificate Authority (CA) for device identity management. It generates CA key pairs, signs Certificate Signing Requests (CSRs), and produces X.509-like JWTs for device certificates. The module is self-contained, uses standard cryptographic primitives (JWK, JWT), and demonstrates a clean PKI pattern that can be reused in any system needing decentralized device authentication.

Defines a generic interceptor gateway that wraps a SerdeGateway and allows chaining of interceptors (e.g., logging, encryption, compression). This is a clean implementation of the middleware/interceptor pattern applied to storage gateways, enabling composable transformations on data flow. It is reusable across any project using a similar gateway abstraction for storage or networking.

An async commit queue that manages pending operations with promises, supporting pause, resume, and cancellation. It provides a `CommitQueue` interface with `add`, `flush`, `pause`, `resume`, and `clear` methods. This is a reusable concurrency primitive suitable for any application needing bounded or cancellable async task processing with flow control.

A simple in-memory implementation of the Gateway interface used for testing and ephemeral storage scenarios. It stores key-value pairs in a Map and supports basic `get`, `put`, `delete`, and `subscribe` operations. This is a clean, self-contained mock that can be reused as a test double or lightweight storage backend in any project using a similar gateway abstraction.