log: demote the four lines that were 90% of debug.log behind /debugrelay

A 13-hour production capture was ~71% "sending: tx", ~16% "Nostr:
discovered .btf peer", ~5% "Relaying wtx", and ~43% of raw lines were
CBlock/CTransaction dumps -- all already under -debug, which operators
run permanently, so -debug was useless as a filter.

The category mechanism gains a verbose tier: "relay" and
"nostrdiscovery" are accepted only with the new /debugrelay flag (which
implies /debug); everything else keeps its current gate. Demoted, with
message text unchanged for anyone grepping it:

  net.h     "sending: tx (N bytes)" (BeginMessage/EndMessage/
            AbortMessage all pick the category from the command, so no
            orphaned "(N bytes)" fragments leak into a plain -debug log)
  main.cpp  "Relaying wtx", "received block:" + CBlock::print, and the
            BitcoinMiner block dump
  nostr.cpp "Nostr: discovered .btf peer" -> "nostrdiscovery"

Pool/worker/payout, [payout], BLOCK ORPHANED/ACCEPTED and share flow
lines are untouched. Because LogPrint dedup keys on category, demoted
lines also keep their burst collapse under /debugrelay.

Closes #35

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nostr.cpp b/src/nostr.cpp
index e2d839c..9bbf74e 100644
--- a/src/nostr.cpp
+++ b/src/nostr.cpp
@@ -1440,7 +1440,7 @@ static bool SeedFromRelay(CNostrKey& key, const string& relay)
                         else if (createdAt > it->second)  it->second = createdAt; // refresh
                     }
                     if (fNew && fDebug)
-                        LogPrint("nostr", "Nostr: discovered .btf peer %s\n", peerAddr.c_str());
+                        LogPrint("nostrdiscovery", "Nostr: discovered .btf peer %s\n", peerAddr.c_str());
                     if (++nPeers > 500) break;
                 }
                 else if (type == "EOSE")