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>

dDashboardServer/DashboardServer.cpp

@@ -73,6 +73,7 @@
 #include "PublicRoutes.h"
 #include "Showcase.h"
 #include "ContrabandRoutes.h"
+#include "PropertyRentRoutes.h"
 #include "FeaturedProperties.h"
 #include "PasswordRecovery.h"
 #include "SettingsRoutes.h"
@@ -526,6 +527,7 @@ int main(int argc, char** argv) {
 	RegisterShowcaseRoutes();
 	FeaturedProperties::RegisterRoutes();
 	ContrabandRoutes::RegisterRoutes();
+	PropertyRentRoutes::RegisterRoutes();
 	RegisterPasswordRecoveryRoutes();
 	RegisterWSRoutes();
 	RegisterDashboardRoutes(); // Must be last - catches all unmatched routes