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, 13 insertions, 0 deletions

diff --git a/src/util.cpp b/src/util.cpp
index 52cda84..a5a4e80 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -7,6 +7,7 @@
 
 
 bool fDebug = false;
+bool fDebugRelay = false;
 
 // In-process cap for debug.log, in bytes. Default matches the 1G trigger of
 // the shipped logrotate policy so a long-running node stays bounded even
@@ -31,10 +32,22 @@ static bool LogCategoryDefaultOn(const char* category)
            strcmp(category, "payout") == 0;
 }
 
+// Categories so noisy they drown out everything else even under -debug:
+// per-message send traces, wallet relay rebroadcasts, raw CBlock dumps and
+// per-address discovery lines made up ~90% of a 13-hour production capture
+// (issue #35). They need /debugrelay, not merely /debug.
+static bool LogCategoryVerboseOnly(const char* category)
+{
+    return strcmp(category, "relay")          == 0 ||
+           strcmp(category, "nostrdiscovery") == 0;
+}
+
 bool LogAcceptsCategory(const char* category)
 {
     if (LogCategoryDefaultOn(category))
         return true;
+    if (LogCategoryVerboseOnly(category))
+        return fDebugRelay;
     return fDebug;
 }