feat: add axon CLI for pub/sub; fix relay hijack context bug

- cmd/axon: new CLI module with keygen, pub, and req subcommands
  - keygen: generate Ed25519 keypair, print hex seed and pubkey
  - pub: sign and publish an event; accepts --kind, --content, --tag
  - req: query/stream events as JSON lines; accepts --kind, --author,
    --tag, --since, --until, --limit, --stream
  - key loaded from --key flag or AXON_KEY env var

- relay/websocket: add Dial() for client-side WebSocket handshake
  (ws:// and wss://, RFC 6455 masking via client:true)

- relay/server: fix broken-pipe on auth by switching hijacked conn
  goroutine from r.Context() to context.Background(); r.Context() is
  cancelled by net/http immediately after Hijack is called

0 files changed, 0 insertions, 0 deletions