feat(portals): add craftable portal blocks replacing hardcoded coordinates

Portal frame crafted from obsidian + ender pearl, combined with crystals
(emerald/amethyst/prismarine) to create world-specific portal blocks.
Stepping on a portal block triggers transfer. Includes resource pack with
vanilla textures, block definitions, crafting recipes, and updated script.

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

lobby-addon/lobby_transfer_BP/manifest.json

@@ -4,7 +4,7 @@
     "name": "Lobby Portal Transfer",
     "description": "Auto-transfers players when they step into portal areas",
     "uuid": "a1b2c3d4-1111-2222-3333-abcdef123456",
-    "version": [1, 0, 4],
+    "version": [1, 1, 0],
     "min_engine_version": [1, 21, 0]
   },
   "modules": [
@@ -12,7 +12,7 @@
       "type": "script",
       "language": "javascript",
       "uuid": "a1b2c3d4-4444-5555-6666-abcdef789012",
-      "version": [1, 0, 4],
+      "version": [1, 1, 0],
       "entry": "scripts/main.js"
     }
   ],
@@ -24,6 +24,10 @@
     {
       "module_name": "@minecraft/server-admin",
       "version": "1.0.0-beta"
+    },
+    {
+      "uuid": "b2c3d4e5-1111-2222-3333-fedcba654321",
+      "version": [1, 0, 0]
     }
   ]
 }