fix: wand listener, killer/survivor spawn commands, double phase exit, generatorManager null check

src/main/java/dev/loki/config/LocationsConfig.java

@@ -109,6 +109,16 @@ public class LocationsConfig {
         return spawns.isEmpty() ? null : spawns.get(0);
     }
 
+    public void setKillerSpawn(Location loc) {
+        // killer-spawn is a single location stored as a list with one entry
+        List<String> list = new java.util.ArrayList<>();
+        list.add(String.format("%s,%.2f,%.2f,%.2f,%.1f,%.1f",
+            loc.getWorld().getName(),
+            loc.getX(), loc.getY(), loc.getZ(),
+            loc.getYaw(), loc.getPitch()));
+        config.set("killer-spawn", list);
+    }
+
     public List<Location> getSurvivorSpawns() {
         return loadLocationList("survivor-spawns");
     }