* fix(security): harden sandbox SSH with mandatory HMAC secret, NetworkPolicy, and nonce replay detection
Closes#25
- Make NEMOCLAW_SSH_HANDSHAKE_SECRET mandatory: server and sandbox both
refuse to start if the secret is empty/unset. Cluster deployments
auto-generate it via openssl rand in the entrypoint script.
- Add Kubernetes NetworkPolicy restricting sandbox port 2222 ingress to
the gateway pod only, preventing lateral movement from other cluster
workloads.
- Add NSSH1 nonce replay detection with a TTL-bounded cache, rejecting
replayed handshakes within the timestamp validity window.
- Add unit tests for verify_preface (valid, replay, expired, bad HMAC,
malformed) and env injection.
* fix(deploy): pass sshHandshakeSecret in fast deploy helm upgrade
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Co-authored-by: John Myers <johntmyers@users.noreply.github.com>
Drew Newberry