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>

migrations/dlu/mysql/60_player_positions.sql

@@ -0,0 +1,14 @@
+/* Where players were, sampled every few seconds by the dashboard for the 3D world view's replays (staff only). Kept for position_history_days. */
+CREATE TABLE IF NOT EXISTS player_positions (
+    character_id BIGINT NOT NULL,
+    time BIGINT NOT NULL,
+    zone_id INT UNSIGNED NOT NULL,
+    instance_id INT UNSIGNED NOT NULL,
+    clone_id INT UNSIGNED NOT NULL DEFAULT 0,
+    x FLOAT NOT NULL,
+    y FLOAT NOT NULL,
+    z FLOAT NOT NULL,
+    PRIMARY KEY (character_id, time),
+    INDEX player_positions_zone_time (zone_id, time),
+    INDEX player_positions_time (time)
+);