fix(peer): gossip pool presents the node's advertised mTLS identity (#1532)

[MichaelTaylor3d]

Root cause — Defect 1, NODE IDENTITY SPLIT (#1532)

The standalone node runs two in-process TLS listeners: the peer-RPC server (:9444) and the dig-gossip connected pool (:9445). The advertised / relay-registered / auto-dialer-pinned peer_id = SHA-256(TLS SPKI DER) comes from the persistent CA-signed NodeCert under node_cert_dir(). But the gossip pool loaded its listener cert/key from a SEPARATE peer-net/node.cert, and — absent that file — dig_peer_protocol::load_ssl_cert fell through to minting a throwaway ChiaCertificate with a DIFFERENT SPKI, hence a DIFFERENT peer_id.

Result: the gossip-pool listener presented an identity that did not match the advertised one, so every relayed/direct dial to this node failed closed with peer_id mismatch: expected <advertised>, got <gossip-cert> — exactly the #1062 Leg B failure. Leg A (dial-by-address) only passed because it accepted whatever cert the listener presented.

Fix (dig-node-only — no cascade)

• gossip_identity_paths(node_cert_dir) returns the NodeCert node.crt/node.key paths; the pool cfg.cert_path/cfg.key_path now point there. dig-gossip only READS those files, so it can never clobber the canonical identity.
• cfg.peer_id is set from the same SPKI via dig_gossip::peer_id_from_tls_spki_der(identity.spki_der()), so the pool's self-dial guard + handshake agree on ONE identity.

One mTLS identity now spans every listener the node runs (peer-RPC, DHT dials, gossip pool).

Blast radius (gitnexus disabled — via read + ripgrep, §2.0 override)

GossipConfig construction is local to peer::spawn/bring-up (one call site). gossip_identity_paths is a new private helper. No public API changed; the gossip cert files move from peer-net/node.cert to the already-persisted peer-net/identity/node.crt (read-only reuse). No dig-gossip / dig-nat change → no release-first cascade.

Tests

• New regression peer::tests::gossip_listener_presents_the_advertised_peer_id — loads the identity from the exact files the pool loads and asserts the reconstructed peer_id equals the advertised NodeCert peer_id.
• Full peer::tests module green (44 passed), incl. the two-node loopback connect + distinct-port bind tests. fmt + clippy clean.

Version

fix → patch: workspace 0.54.0 → 0.54.1, dig-node-core 0.16.0 → 0.16.1.

Docs

SPEC §18 (env/ports) + DEVELOPMENT_LOG updated with the one-identity-across-listeners contract.

Acceptance

main re-runs #1062 Leg B (relayed connect via the REAL relay.dig.net). The v0.54.x pointer stays HELD until Leg B is green. Defects 2 + 3 are separate (see the report); this PR closes Defect 1, the primary blocker.

🤖 Generated with Claude Code

[MichaelTaylor3d]

PASS (correctness gate). Verified against the #1532 Defect-1 fix:

• gossip_identity_paths() (peer.rs:692) returns node_cert_dir/node.crt + node.key — byte-exact the files dig_tls::NodeCert persists (CERT_FILE="node.crt", KEY_FILE="node.key" in dig-tls 0.3.0 node_cert.rs:40-41). dig-gossip loads them read-only via load_ssl_cert; never clobbers.
• cfg.peer_id = dig_gossip::peer_id_from_tls_spki_der(identity.spki_der()) = SHA-256(SPKI DER) = identity.peer_id() = the advertised/registered/pinned peer_id (peer.rs:1393,1434). One NodeCert identity spans :9444 (peer-RPC) and :9445 (gossip pool).
• No production throwaway path remains: NodeCert is written (line 1393) before GossipConfig (line 1420), so the files exist and dig-gossip loads rather than mints. The only self-minted cert left is a pool-stats unit test (lib.rs:4086) that does no peer_id pinning — not the identity path.
• Regression test gossip_listener_presents_the_advertised_peer_id passes locally and genuinely reconstructs the advertised peer_id from the exact files gossip_identity_paths returns; it also implicitly guards dig-tls filename drift (a renamed CERT_FILE would fail the read).
• SPEC §18 / ports section + DEVELOPMENT_LOG accurate. patch bump 0.54.0->0.54.1 (+ dig-node-core 0.16.0->0.16.1) correct for a behavior-preserving fix; both manifests agree.

Non-gating note (resolved): gossip_identity_paths re-hardcodes the literals "node.crt"/"node.key" that dig-tls owns as private consts. Mitigated by the regression test (drift would fail the read), but dig-tls could export these filenames for consumption. Tracked as a nicety, not a blocker.