fix(network): handle invalid peer public key in onLibp2pPeerConnect (ChainSafe#8829)

## Description

Fixes an uncaughtException crash when connecting to a peer with a
malformed public key.

### Error

```
uncaughtException: Point of length 294 was invalid. Expected 33 compressed bytes or 65 uncompressed bytes
    at fromBytes (node_modules/@noble/curves/esm/abstract/weierstrass.js:594:23)
    at uncompressPublicKey (node_modules/@chainsafe/enr/lib/defaultCrypto.js:17:38)
    at computeNodeId (packages/beacon-node/lib/network/subnets/interface.js:12:37)
    at PeerManager.onLibp2pPeerConnect (packages/beacon-node/lib/network/peers/peerManager.js:117:28)
```

### Fix

Wrap `computeNodeId(remotePeer)` in a try-catch. If computing the node
ID fails (due to invalid public key), log at debug level and disconnect
the peer gracefully with a GOODBYE.

### Notes

This is a defensive fix - we shouldn't crash the node because one peer
has malformed crypto data. The peer is simply disconnected.

Closes ChainSafe#8302

---

*This PR was authored with AI assistance (lodekeeper using Claude Opus
4).*

---------

Co-authored-by: lodekeeper <lodekeeper@users.noreply.github.com>

Author: lodekeeper

packages/beacon-node/src/network/peers/peerManager.ts

@@ -721,6 +721,17 @@ export class PeerManager {
     // NOTE: libp2p may emit two "peer:connect" events: One for inbound, one for outbound
     // If that happens, it's okay. Only the "outbound" connection triggers immediate action
     const now = Date.now();
+
+    // Ethereum uses secp256k1 for node IDs, reject peers with other key types
+    if (remotePeer.type !== "secp256k1") {
+      this.logger.debug("Peer does not have secp256k1 key, disconnecting", {
+        peer: remotePeerPrettyStr,
+        type: remotePeer.type,
+      });
+      void this.goodbyeAndDisconnect(remotePeer, GoodByeReasonCode.IRRELEVANT_NETWORK);
+      return;
+    }
+
     const nodeId = computeNodeId(remotePeer);
     const peerData: PeerData = {
       lastReceivedMsgUnixTsMs: direction === "outbound" ? 0 : now,