Test Details Overview

Add peering-only (networking-only) node mode (#5107)

Introduce a --peering_only mode for nodes that only participate in the
peer-to-peer network and do not maintain a ledger. These are intended for
the DNS bootstrap entries, where a node must be reachable and gossip peers
but has no need to spend IO/CPU keeping the ledger current.

A peering-only node keeps a genesis-only store and disables the
ledger-consuming subsystems (schedulers, active elections, bootstrap sync
and server, vote/cementing/backlog processing, rebroadcasters, voting), and
drops incoming publish/confirm_ack at the message boundary so no blocks or
votes are processed.

To keep peering-only nodes from degrading peers that do serve a ledger, a
node advertises a no_ledger capability in the v3 handshake (and the
nf_peering_node telemetry maker). Peers that understand the capability
exclude peering-only nodes from bootstrap candidate selection and
rep-crawler targets, while still gossiping them normally so they remain
useful for peer discovery.

The capability describes the property (no ledger); the mode name describes
the role (peering only). "light" was avoided as it collides with both
pruned nodes and light wallets.

Covered by network.peer_discovery_via_peering_only_node, which asserts that
two nodes knowing only a peering-only node discover each other through it.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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Type: commit

Hash: ac611e3b3ec97131a79d3a17be6160b7c91a1983

Created: today

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gr0v1ty/nano-node:ac611e3b3ec97131a79d3a17be6160b7c91a1983