MailboxGUI

# MailboxGUI v3.1.1

This is a small maintenance update focused on Citizens NPC selector usability, language cleanup, and config comment cleanup.

## Added

- Added left-click cancellation while in NPC selection mode.
- Left-click cancel now works for both:
- Set Post Office NPC
- Remove Post Office NPC
- Added the new language key:
- `admin-npc-selector-cancelled`

## Changed

- NPC selector prompts now explain that admins can right-click an NPC to select it or left-click anywhere to cancel.
- Admin NPC Tools GUI lore now includes the left-click cancel instruction.
- Bundled language files were updated to `file-version: 3`.
- Cleaned and corrected NPC setup/removal wording across bundled language files.
- Removed the plugin version line from the top comment area of `config.yml` so the config header does not need to change every release.

## Fixed

- Fixed players/admins being stuck in NPC selection mode if they could not successfully update or remove an NPC.
- Fixed NPC selector mode not having a left-click cancel path.
- Fixed missing or incorrect NPC selector language text in several bundled language files.

## Upgrade Notes

- No mailbox data reset is required.
- No config reset is required.
- `config-version` was not changed because the config structure did not change.
- Existing language files using `file-version: 2` will upgrade to `file-version: 3`.
- The language upgrader updates old default NPC selector text while preserving customized server language edits.

## Compatibility

- Minecraft/server compatibility remains unchanged from the previous 3.1.x release.
- Citizens is required for Post Office NPC features.
- Vault is only required for economy mail features.
- Dynmap remains optional for map marker support.