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>

dGame/dUtilities/DashboardNotify.h

@@ -0,0 +1,29 @@
+#ifndef __DASHBOARDNOTIFY__H__
+#define __DASHBOARDNOTIFY__H__
+
+#include <string>
+
+#include "dCommonVars.h"
+
+/**
+ * Tells the web dashboard (through master) which rows this world server just wrote, so pages showing them update
+ * right away. Changes are collected and sent in one message every half second; repeats in between are merged.
+ */
+namespace DashboardNotify {
+	void Changed(const std::string& table, LWOOBJID id = 0);
+
+	// Send what has been collected. Called from the world server loop; `force` sends immediately (shutdown).
+	void Flush(bool force = false);
+
+	// Report where this world's players are, every few seconds (called from the world server loop)
+	void SendPlayerPositions(uint32_t instanceId);
+
+	// Show a dashboard announcement to every player in this world
+	void Announce(const std::string& title, const std::string& message);
+
+	// The announcement's line in chat: "Title: message", without the colon after a title that already ends in
+	// punctuation ("Challenge complete! Builders: ...")
+	std::string ChatLine(const std::string& title, const std::string& message);
+}
+
+#endif  //!__DASHBOARDNOTIFY__H__