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.

addons/gut/source_code_pro.fnt.import

@@ -0,0 +1,17 @@
+[remap]
+
+importer="font_data_bmfont"
+type="FontFile"
+uid="uid://cfawt18qr4256"
+path="res://.godot/imported/source_code_pro.fnt-042fb383b3c7b4c19e67c852f7fbefca.fontdata"
+
+[deps]
+
+source_file="res://addons/gut/source_code_pro.fnt"
+dest_files=["res://.godot/imported/source_code_pro.fnt-042fb383b3c7b4c19e67c852f7fbefca.fontdata"]
+
+[params]
+
+fallbacks=[]
+compress=true
+scaling_mode=2