chore: release version 2.3.5 and refactor lobby

Bump export_presets.cfg version to 2.3.5. Update CHANGELOG_DRAFT.md.
Refactor lobby.gd into LobbyChat, LobbyMainMenu, LobbyRoomList, LobbyRoom.
Move Nakama config to environment variables in nakama_manager.gd.
Derive auth_manager.gd encryption key from OS.get_unique_id().sha256_text().
Remove Steam email auth fallback. Require auth ticket.
Make GachaManager.pull() async in gacha_panel.gd.
Remove dummy wallet seeding. Add store_type to IAP payload.
Validate IAP receipts server-side in economy.lua.
Register gacha module in main.lua.
Clean backend_service.gd stubs.
Fix featured_banners type safety in gacha_manager.gd. Guards non-array responses.
Move tiles_armagedon_a1.res to assets/models/meshes/. Fix import fallback_path.

project.godot

@@ -15,7 +15,7 @@ compatibility/default_parent_skeleton_in_mesh_instance_3d=true
 [application]
 
 config/name="Tekton Dash Armageddon"
-config/version="2.3.4"
+config/version="2.3.5"
 run/main_scene="res://scenes/ui/boot_screen.tscn"
 config/features=PackedStringArray("4.6", "Forward Plus")
 boot_splash/bg_color=Color(0.16470589, 0.6745098, 0.9372549, 1)
@@ -59,7 +59,7 @@ window/stretch/mode="viewport"
 
 [editor_plugins]
 
-enabled=PackedStringArray("res://addons/com.heroiclabs.nakama/plugin.cfg", "res://addons/enhanced_gridmap/plugin.cfg", "res://addons/godotsteam/plugin.cfg")
+enabled=PackedStringArray("res://addons/com.heroiclabs.nakama/plugin.cfg", "res://addons/enhanced_gridmap/plugin.cfg", "res://addons/godotsteam/plugin.cfg", "res://addons/gut/plugin.cfg")
 
 [file_customization]