Completes the operator side of the relay integration:
- deploy/relay/: reference docker-compose + config.toml for a locked-down
nostr-rs-relay wired to the backend's gRPC admission (host networking so the
loopback admission socket stays private). Clearly marked a template to pin/
verify against the operator's nostr-rs-relay version.
- docs/operations/RELAY.md: what it is (inbox relay, not the only relay), the
admission architecture, the three write policies + NIP-13 PoW, bundled vs
external, verification, and the seam's modularity. Linked from OPERATOR_SETUP.
- .env.example: the RELAY_* block (all off/placeholder).
Backend relay integration (config → seam → policy → gRPC admission →
capabilities → NIP-05 → packaging/docs) is now complete. Client DM stack next.
