Build power requirements from rune item_power_grant

PowerReq lists now come from the rune JSON on world and login: level from
power_value, skill and power prereqs from power_granted_skills/powers.
The DB table is no longer read.

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

src/engine/server/login/LoginServer.java

@@ -384,6 +384,9 @@ public class LoginServer {
         Logger.info("Initializing PowersManager.");
         PowersManager.initPowersManager(false);
 
+        Logger.info("Loading Rune Power Requirements");
+        PowerReq.loadRunePowers();
+
         RuneBase.LoadAllRuneBases();
         BaseClass.LoadAllBaseClasses();
         PromotionClass.LoadAllPromotions();