feat: optional property rent

Off unless property_rent_enabled is on. Each property world's rent comes from its PropertyTemplate
row (minimumPrice every rentDuration x durationType; Block Yard is free), unless the new Property
Rent dashboard page sets another price or period (property_rent_manage). Rent is taken from the
owner's coins shortly after their character loads, with a mail receipt; unpaid rent is mailed and,
after property_rent_grace_days, makes the property private until it is paid, like live. The
property management component refuses public or best friends privacy while rent is overdue and a
property world that loads overdue makes itself private. Property game messages are unchanged.

Fixes #943

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

dWorldServer/WorldServer.cpp

@@ -7,6 +7,7 @@
 #include "master/MessageCapture.h"
 #include "MessageInspector.h"
 #include "Contraband.h"
+#include "PropertyRent.h"
 #include "LiveEvents.h"
 #include <iostream>
 #include <string>
@@ -955,6 +956,7 @@ void LoadPlayer(const SystemAddress& sysAddr) {
 
 			// Contraband is flagged (and removed if its entry says so) before the character is saved and sent
 			Contraband::CheckOnLoad(player);
+			PropertyRent::OnOwnerLoaded(player);
 
 			// Update the characters xml to ensure the update above is not only saved, but so the client picks up on the changes.
 			c->SaveXMLToDatabase();