Secure Device Pairing Protocol

Description

A secure protocol for pairing two devices will be implemented. The flow uses a human-readable BIP39 mnemonic code to establish a secure, end-to-end encrypted session, after which devices are mutually trusted.

Implementation Notes

• The complete state machine and logic will be implemented in src/services/networking/protocols/pairing/.
• The PairingProtocolHandler manages the initiator and joiner roles.
• Cryptographic operations, including challenge-response using ed25519-dalek, are handled by pairing/security.rs.
• Multi-process integration tests (device_pairing_test.rs, device_persistence_test.rs) validate the real-world functionality.

Acceptance Criteria

• An initiator can generate a 12-word pairing code.
• A joiner can use the code to discover and connect to the initiator.
• Devices successfully exchange keys and establish a trusted relationship.
• Paired device information is persisted securely for automatic reconnection.