Remove peer exchange from main; it was merged unreviewed (#27)

PR #25 was opened, reviewed and approved as a single-file change to net.cpp:
the .btf peer cache, +169/-0. I then pushed peer exchange and a /port option
onto that same branch while the PR was open, which silently widened it to six
files. The merge carried all of it in.

Nothing about the peer exchange had been validated. Its two-node test never
completed -- node B could not dial node A at all -- so what landed on main is
unproven network protocol code that no one agreed to take.

This restores main to what #25 actually described. The peer cache stays, with
its runtime numbers (36.3s to 2.1s to first peer). #26 stays. What comes out:

- the "btfpeers" message, both directions
- BtfPexCollect / BtfPexAccept and the per-message caps
- CNode::nLastPexRecv
- the `desc` field on the cached peer record
- BtfLocalDescriptor / BtfSecpContext
- /port

Peer exchange returns as its own pull request once its test passes. The /port
option is worth having on its own -- two nodes cannot share a machine without
it, which is what blocked the test -- and should go up separately rather than
ride along again.

Release v1.2.2 is unaffected: it was built from ba2de82, before either merge.

1 files changed, 0 insertions, 8 deletions

diff --git a/src/nostr.h b/src/nostr.h
index b5eb5e3..04149e3 100644
--- a/src/nostr.h
+++ b/src/nostr.h
@@ -82,14 +82,6 @@ bool BtfGetIdentity(unsigned char pubkey[32], unsigned char enc_sk[32]);
 // This node's printable .btf address, or "" if the identity failed to load.
 std::string BtfLocalAddress();
 
-// This node's own signed descriptor, ready to hand to a peer over the wire.
-// "" until ThreadBtfAccept has registered at a rendezvous.
-std::string BtfLocalDescriptor();
-
-// The shared secp256k1 context, for btf::VerifyDescriptor (which takes it as
-// void* to keep headers free of secp). NULL if the identity failed to load.
-void* BtfSecpContext();
-
 // Resolve a .btf address via the public discovery relays: fetch the owner's
 // self-certified descriptor and return its meeting node ("host:port") and
 // x25519 public key for the end-to-end channel.