feat(capture): record whole packets of an account, a character or everything on every server

Staff arm a packet capture on the dashboard; master passes MESSAGE_CAPTURE_CONTROL ARM to
every world, auth and chat and arms its own. Each server's PacketCapture tap (dServer receive,
and a send hook in RakPeer::Send so replica constructions are seen too) records into one
preallocated chunk per server and ships sealed chunks through master on the main loop when
capture_flush_bytes or capture_flush_interval_ms is reached; past capture_buffer_max_mb the
oldest chunks are dropped and the dashboard records a gap. Nothing is armed: one flag check.

- targets: an account (from its login; packets before the login are kept per connection
  and added once auth or the world knows whose they are), a character (from when it is
  picked), or everything; up to 8 at once (a bit each in the record mask)
- worlds and auth record their clients' packets and the master link messages of a captured
  player (session keys by name, zone transfers by request, player added/removed, migration);
  chat finds the player in each packet; master records server traffic for everything
- secrets are never recorded: structs that carry them (login request, login response user
  key, world validation session key, session key messages between servers) are read,
  blanked and written again before recording; auth keeps only the handshake and login
- PacketDecoder: a registry by service and message id names every packet and decodes the
  registered structs; CaptureBundle is the file format (DLUBNDL1, metadata, records);
  CaptureTools orders records on one timeline, pulls movement out, makes bundles portable
  or anonymous and diffs replays
- the dashboard keeps packet captures in message_capture_sessions (capture_kind 1) and
  their packets in a file under capture_dir, one write per batch; arming is audited
- MESSAGE_CAPTURE_CONTROL/DATA only gain appended enum values and trailing fields

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dNet/dServer.cpp

@@ -15,6 +15,8 @@
 #include "CommonPackets.h"
 #include "MasterPackets.h"
 #include "ZoneInstanceManager.h"
+#include "PacketCapture.h"
+#include "master/MessageCapture.h"
 #include "StringifiedEnum.h"
 #include "GeneralUtils.h"
 #include "TrafficStats.h"
@@ -134,6 +136,9 @@ dServer::dServer(
 		mPeer->AttachPlugin(mReplicaManager);
 		mPeer->SetNetworkIDManager(mNetIDManager);
 	}
+
+	// The dashboard's packet capture records what goes through the listening peer and, for a captured player, the master link
+	PacketCapture::Attach(serverType, mPeer, mMasterPeer, zoneID, static_cast<uint32_t>(instanceID));
 }
 
 dServer::~dServer() {
@@ -148,6 +153,7 @@ Packet* dServer::ReceiveFromMaster() {
 	CountTraffic(packet, TrafficStats::Peer::MASTER);
 	if (packet) {
 		if (packet->length < 1) { mMasterPeer->DeallocatePacket(packet); return nullptr; }
+		PacketCapture::OnReceiveFromMaster(packet);
 
 		switch (packet->data[0]) {
 		case ID_DISCONNECTION_NOTIFICATION:
@@ -201,6 +207,15 @@ Packet* dServer::ReceiveFromMaster() {
 					break;
 				}
 
+				case MessageType::Master::MESSAGE_CAPTURE_CONTROL: {
+					// Packet captures run on every server; the game message inspector's start and stop go to the world's own handler
+					MessageCaptureControl control;
+					if (!control.Deserialize(inStream)) break;
+					if (control.action != eMessageCaptureControl::ARM && control.action != eMessageCaptureControl::DISARM) return packet;
+					PacketCapture::Control(control);
+					break;
+				}
+
 				// When we handle these packets in World instead dServer, we just return the packet's pointer.
 				default:
 					return packet;
@@ -219,6 +234,7 @@ Packet* dServer::ReceiveFromMaster() {
 Packet* dServer::Receive() {
 	Packet* packet = mPeer->Receive();
 	CountTraffic(packet, PeerOfConnections());
+	PacketCapture::OnReceive(packet);
 	return packet;
 }
 
@@ -297,6 +313,7 @@ void dServer::UpdateBandwidthLimit() {
 }
 
 void dServer::Shutdown() {
+	PacketCapture::Detach();
 	if (mPeer) {
 		mPeer->Shutdown(1000);
 		RakNetworkFactory::DestroyRakPeerInterface(mPeer);