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, 4 insertions, 0 deletions

diff --git a/src/util.h b/src/util.h
index f2ea23f..c47b8a7 100644
--- a/src/util.h
+++ b/src/util.h
@@ -87,6 +87,10 @@ inline T& REF(const T& val)
 
 extern bool fDebug;
 
+// /debugrelay: the per-message firehose ("relay" and "nostrdiscovery"
+// categories) that even -debug keeps off. See LogAcceptsCategory().
+extern bool fDebugRelay;
+
 // debug.log is rolled to debug.log.old once it grows past this many bytes
 // (set from -maxdebugfilesize, in MB; 0 disables the check). See the roll
 // site in OutputDebugStringF() below.