fix(transfer): use transferPlayer() beta API and enable experiments in level.dat

Switch from runCommand("transfer ...") to the @minecraft/server-admin
transferPlayer() function for reliable server-to-server transfers.
Enable Beta APIs experiment (gametest flag) in all 4 world level.dat files.
Add spawn protection to prevent transfer loops on arrival.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hub-return-addon/hub_return_transfer_BP/manifest.json

@@ -4,7 +4,7 @@
     "name": "Hub Return Transfer",
     "description": "Transfers players back to lobby when they step on the return portal",
     "uuid": "b2c3d4e5-1111-2222-3333-fedcba654321",
-    "version": [1, 0, 1],
+    "version": [1, 0, 3],
     "min_engine_version": [1, 21, 0]
   },
   "modules": [
@@ -12,14 +12,18 @@
       "type": "script",
       "language": "javascript",
       "uuid": "b2c3d4e5-4444-5555-6666-fedcba987654",
-      "version": [1, 0, 1],
+      "version": [1, 0, 3],
       "entry": "scripts/main.js"
     }
   ],
   "dependencies": [
     {
       "module_name": "@minecraft/server",
-      "version": "2.0.0"
+      "version": "1.17.0"
+    },
+    {
+      "module_name": "@minecraft/server-admin",
+      "version": "1.0.0-beta"
     }
   ]
 }

hub-return-addon/hub_return_transfer_BP/scripts/main.js

@@ -1,4 +1,5 @@
 import { world, system, ItemStack } from "@minecraft/server";
+import { transferPlayer } from "@minecraft/server-admin";
 
 const LOBBY_HOST = "10.0.0.247";
 const LOBBY_PORT = 19132;
@@ -6,9 +7,12 @@ const COMPASS_ID = "minecraft:recovery_compass";
 const PORTAL_PROP = "hub_portal_location";
 const PORTAL_RADIUS = 3;
 const TRANSFER_COOLDOWN = 5000; // 5 seconds
+const SPAWN_PROTECTION = 10000; // 10 seconds — ignore portal detection after spawn
 
 // Track recently transferred players
 const recentTransfers = new Map();
+// Track when players spawned (to prevent transfer loop on arrival)
+const spawnTimes = new Map();
 
 function doTransfer(player) {
   const now = Date.now();
@@ -21,7 +25,7 @@ function doTransfer(player) {
   world.sendMessage(`§a${player.name} is returning to the Hub...`);
 
   try {
-    player.runCommand(`transfer ${player.name} ${LOBBY_HOST} ${LOBBY_PORT}`);
+    transferPlayer(player, { hostname: LOBBY_HOST, port: LOBBY_PORT });
   } catch (e) {
     player.sendMessage(`§cTransfer failed: ${e.message}`);
   }
@@ -45,6 +49,8 @@ function giveCompassIfMissing(player) {
 
 world.afterEvents.playerSpawn.subscribe((event) => {
   const player = event.player;
+  // Mark spawn time for portal protection (prevents transfer loop on arrival)
+  spawnTimes.set(player.name, Date.now());
   // Small delay to let inventory load
   system.runTimeout(() => {
     try {
@@ -82,9 +88,14 @@ system.runInterval(() => {
   const players = world.getAllPlayers();
 
   for (const player of players) {
+    // Skip if recently transferred (cooldown)
     if (recentTransfers.has(player.name) && now - recentTransfers.get(player.name) < TRANSFER_COOLDOWN) {
       continue;
     }
+    // Skip if player just spawned (prevents loop when arriving from lobby)
+    if (spawnTimes.has(player.name) && now - spawnTimes.get(player.name) < SPAWN_PROTECTION) {
+      continue;
+    }
 
     const pos = player.location;
     const dx = Math.abs(pos.x - portal.x);
@@ -131,7 +142,7 @@ function handleChatCommand(player, msg) {
   return false;
 }
 
-// Try beforeEvents.chatSend (pre-release in some BDS versions)
+// Listen for chat commands — try beforeEvents first (beta API), fall back gracefully
 try {
   world.beforeEvents.chatSend.subscribe((event) => {
     const msg = event.message.trim().toLowerCase();
@@ -141,11 +152,13 @@ try {
       system.run(() => handleChatCommand(player, msg));
     }
   });
-} catch {
-  // chatSend not available — fall back to polling player chat via scriptEvent
+} catch (e) {
+  // beforeEvents.chatSend requires beta API — chat commands won't work via chat,
+  // but compass and portal transfers still function
+  world.sendMessage("§e[Hub] §fChat commands (!hub, !lobby) unavailable — use compass or portal instead.");
 }
 
-// Fallback: listen for scriptevent commands (players run: /scriptevent hub:cmd <command>)
+// scriptEvent fallback — players can use: /scriptevent hub:cmd hub
 system.afterEvents.scriptEventReceive.subscribe((event) => {
   if (event.id !== "hub:cmd") return;
   const player = event.sourceEntity;