feat: web dashboard and playground work

The NexusDashboard-parity dashboard (dDashboardServer) and everything built on it on the experimental branch:
accounts, characters, properties and moderation tools, permissions shared with in-game slash commands, economy
reports, World 3D and property 3D views with client scenery, scheduled events (features, vanity changes, live
events, announcements, restarts), vanity files and events, the CDClient browser, the message inspector with saved
captures, chat filter tools, community challenges, live ops, the AI moderator helper, and the server-side changes
they need.

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

dNet/dServer.h

@@ -2,6 +2,7 @@
 #include <string>
 #include <chrono>
 #include <csignal>
+#include <functional>
 #include "RakPeerInterface.h"
 #include "ReplicaManager.h"
 #include "NetworkIDManager.h"
@@ -43,6 +44,11 @@ public:
 	virtual void Send(RakNet::BitStream& bitStream, const SystemAddress& sysAddr, bool broadcast);
 	void SendToMaster(RakNet::BitStream& bitStream);
 
+	// Sees every packet Send sends, before it goes out (the dashboard's message inspector sets it only while it
+	// captures, so sending costs nothing extra otherwise). Pass nullptr to remove it.
+	using SendObserver = std::function<void(const RakNet::BitStream& bitStream, const SystemAddress& sysAddr, bool broadcast)>;
+	void SetSendObserver(SendObserver observer) { mSendObserver = std::move(observer); }
+
 	void Disconnect(const SystemAddress& sysAddr, eServerDisconnectIdentifiers disconNotifyID);
 
 	bool IsConnected(const SystemAddress& sysAddr);
@@ -109,4 +115,5 @@ protected:
 	int mMasterPort;
 	std::chrono::steady_clock::time_point mStartTime = std::chrono::steady_clock::now();
 	std::string mMasterPassword;
+	SendObserver mSendObserver;
 };