Add the static world ID counter and static flag

Static world objects take IDs from DbManager.nextStaticID(), counting down
from -2 in a fixed load order (W2). Runtime negative IDs (loot, forged and
contract items, pets and minions) now share ItemManager.lastNegativeID,
which starts at -1,000,000; Mob.staticID is gone. Boot fails if the static
counter reaches the runtime range. AbstractWorldObject gets a
staticWorldObject flag for the factories to set. Nothing uses either yet.

Value changes: runtime negative IDs start at -1,000,001 (-1,000,000 for
forged items) instead of -1; pets and minions draw from the item counter.

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

src/engine/gameManager/DbManager.java

@@ -23,10 +23,15 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.EnumMap;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
 
 public enum DbManager {
     DBMANAGER;
 
+    // Static world IDs count down from -2 (-1 means "not found"); runtime negative IDs start below them.
+    public static final int RUNTIME_ID_START = -1_000_000;
+    private static final AtomicInteger lastStaticID = new AtomicInteger(-1);
+
     public static final dbAccountHandler AccountQueries = new dbAccountHandler();
     public static final dbBaneHandler BaneQueries = new dbBaneHandler();
 
@@ -70,6 +75,17 @@ public enum DbManager {
     public static Hasher hasher;
     private static HikariDataSource connectionPool = null;
 
+    // Only the static world factories may call this, in the fixed load order (W2); never renumber.
+    public static int nextStaticID() {
+
+        int staticID = lastStaticID.decrementAndGet();
+
+        if (staticID <= RUNTIME_ID_START)
+            throw new IllegalStateException("Static world ID " + staticID + " reached the runtime ID range at " + RUNTIME_ID_START);
+
+        return staticID;
+    }
+
     public static AbstractGameObject getObject(GameObjectType objectType, int objectUUID) {
 
         AbstractGameObject outObject = null;