feat: Add Nip42 handler

[Anshumancanrock]

Description

Second PR for NIP-42 (follows #622). This one wires everything up so the adapter now sends a challenge on connect and there's a handler to verify the client's AUTH response.

• WebSocketAdapter generates a random challenge on connect and sends ["AUTH", <challenge>]
• new AuthMessageHandler verifies kind 22242 events (checks id, sig, timestamp, challenge tag, relay domain)
• on success the pubkey gets stored in a per-connection set, cleared on disconnect
• kind 22242 is blocked from the normal EVENT pipeline so it can't hit storage
• messageHandlerFactory routes AUTH messages to the new handler
• extended IWebSocketAdapter with getChallenge(), getAuthenticatedPubkeys(), addAuthenticatedPubkey()

Related Issue

Closes #619

Motivation and Context

With the types from #622 in place, this wires up the actual auth flow so connections can be tied to a pubkey. Sets things up for NIP-70 protected events next.

How Has This Been Tested?

Added 20 new tests across the handler, adapter and factory specs.

Types of changes

• Non-functional change (docs, style, minor refactor)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my code changes.
• I added a changeset, or this is docs-only and I added an empty changeset.
• All new and existing tests passed.

[changeset-bot]

🦋 Changeset detected

Latest commit: 3f43783

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
nostream	Minor

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[coveralls]

coverage: 65.411% (+0.3%) from 65.108% — Anshumancanrock:nip42-handler into cameri:main

[Copilot]

Pull request overview

Adds NIP-42 challenge/response authentication to the WebSocket ingestion path by issuing an AUTH challenge on connect and validating incoming AUTH events (kind 22242) in a dedicated handler, while preventing 22242 events from being published through the normal EVENT pipeline.

Changes:

• Send ["AUTH", <challenge>] on new WebSocket connections and track authenticated pubkeys per connection.
• Introduce AuthMessageHandler and route AUTH messages to it via messageHandlerFactory.
• Block kind 22242 from the standard EVENT handler to avoid persistence/pipeline handling.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/adapters/web-socket-adapter.ts	Generates/sends NIP-42 challenges on connect; tracks authenticated pubkeys and clears them on disconnect.
src/handlers/auth-message-handler.ts	Implements validation for kind 22242 AUTH events (id, sig, timestamp, challenge tag, relay domain) and records authenticated pubkeys.
src/handlers/event-message-handler.ts	Rejects kind 22242 when sent via EVENT to keep auth events out of the normal event pipeline.
src/factories/message-handler-factory.ts	Routes AUTH messages to the new AuthMessageHandler.
src/@types/adapters.ts	Extends IWebSocketAdapter with challenge/authenticated-pubkeys accessors/mutator.
test/unit/adapters/web-socket-adapter.spec.ts	Adds coverage for challenge emission and new adapter auth-related methods.
test/unit/handlers/auth-message-handler.spec.ts	Adds unit tests for AUTH validation success/failure cases.
test/unit/factories/message-handler-factory.spec.ts	Adds a test ensuring AUTH messages produce AuthMessageHandler.
.changeset/funky-coins-know.md	Declares a minor release for NIP-42 AUTH wiring.

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[Anshumancanrock]

Hi @cameri , This PR is up for review.

[Ferryx349]

Overall the changes look great, just few nits: