Migrate to YAW/2 protocol: WebRTC transport, anchor signaling, nacl/box crypto
Replace the original raw-TCP peer connections and Blowfish/RSA-era design with
the YAW/2 protocol stack:
Transport
- internal/mesh/peer.go: raw TCP + manual ECDH replaced with pion/webrtc
DataChannels (ICE, DTLS, SCTP). Peers negotiate via sealed offer/answer/
candidate exchange rather than direct dialling.
- internal/nat: deleted — ICE subsumes everything this package was going to do.
Signaling
- cmd/anchor: new WebSocket signaling server (replaces cmd/relay). Verifies
Ed25519 challenge/join signatures, routes opaque nacl/box blobs, broadcasts
peer-join/peer-leave events. Never sees plaintext signaling content.
- internal/anchor: new anchor client. Manages PeerConnection lifecycle,
decides offerer by peer-id comparison, seals/opens signaling payloads with
nacl/box, implements mesh.Anchor.
Crypto (internal/crypto)
- PeerID encoding: base64url → lowercase hex (64 chars, YAW/2 §2).
- Sign/Verify: hex signatures throughout.
- Added CurvePublicKey/CurvePrivateKey: X25519 keys derived from Ed25519
identity via Montgomery conversion (filippo.io/edwards25519), matching
libsodium's crypto_sign_ed25519_*_to_curve25519.
- Added SignalingBox/SignalingOpen: nacl/box (XSalsa20-Poly1305) seal/open
for signaling payloads.
Wire types (internal/proto)
- ChatMessage gains Mid (random 16-byte hex) for mesh deduplication (§8).
- FileChunk removed from PeerMessage — chunks go on a separate binary
DataChannel labelled "f:<xid>"; FileDone added.
- New types: SignalingPayload, AnchorMessage, HelloMessage, HelloBindString.
- PeerID.Short() now returns first 16 hex chars grouped in 4s.
- IPC: CmdConnect removed; CmdJoinNetwork/CmdLeaveNetwork added;
EvtSessionReady added (fires when DataChannel opens and hello is received).
IPC (internal/ipc)
- join_network/leave_network replace connect (direct TCP dial).
- Network joins are context-scoped: leave_network or client disconnect
cancels the anchor connection cleanly.
README updated to reflect new project layout, getting-started commands,
IPC protocol, and roadmap state.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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