feature: update validator and orchestrator to use libp2p node

[noot]

• implement shared libp2p node which handles the authentication protocol
• implement validator libp2p node with handling of required request-response message types (hardware challenge)
• implement orchestrator libp2p node with handling of required request-response message types (invite, get task logs, restart task)
• update validator and orchestrator to use libp2p node when started
• remove iroh from validator and orchestrator

[Copilot]

Pull Request Overview

This PR replaces direct P2P client integrations with a shared libp2p Service using channels, refactors hardware challenges and orchestration invites/log retrieval to use the new Service, and updates startup and API routes accordingly.

• Introduce a single P2PService and request/response channels in both validator and orchestrator.
• Refactor HardwareChallenge/HardwareValidator to send requests via mpsc::Sender instead of P2PClient.
• Update orchestrator’s NodeInviter and API route handlers to enqueue P2P requests on channels.

Reviewed Changes

Copilot reviewed 25 out of 26 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/validator/src/validators/hardware_challenge.rs	Swapped out direct P2PClient calls for a channel-based request
crates/validator/src/p2p/mod.rs	Added Service to bridge hardware challenge channel to libp2p
crates/orchestrator/src/node/invite.rs	Refactored NodeInviter to send invites via channel
crates/orchestrator/src/api/routes/nodes.rs	Updated restart/log routes to enqueue and await channel responses
crates/orchestrator/src/main.rs	Initialize and spawn P2PService and wire invite/get/restart channels

Comments suppressed due to low confidence (1)

crates/validator/src/validators/hardware_challenge.rs:80

• The random_challenge method is still inside an impl<'a> HardwareChallenge<'a> block even though the struct no longer has a lifetime parameter. Change the impl to impl HardwareChallenge to match the updated struct.

    fn random_challenge(

[noot]

closing in favour of #622