Fixed
- **World resets working again** — Reverted the `WorldCreator.ofKey()` change introduced in 1.1.6. In Paper 26.1, after a world is unloaded via `Bukkit.unloadWorld()`, its dimension key remains registered internally for the session. Re-creating with the same custom-namespace key (e.g. `bubblereset:resource_world`) was silently rejected by Paper, causing `Bukkit.createWorld()` to return `null` and leaving the world permanently missing — players received the "under Maintenance" message on every teleport attempt.

Clarified (no code change)
- **World folder location is correct** — Paper 26.1 follows Minecraft's dimension storage architecture: all worlds are stored as dimensions inside the primary server level (`world/dimensions/minecraft/<name>/`). Root-level world folders are no longer created by Paper 26.x. This is expected behavior; worlds function identically — teleports, resets, borders, and game rules all work as before.