Add Kit GUI (menu/anvil) and integrate MenuListener

Introduce a full chest-based kit selection UI and anvil search: add Menu, MenuHolder, KitSelectorMenu, KitItemFactory, AnvilSearchMenu (with AnvilSearchTracker) and a central MenuListener to dispatch menu and anvil interactions. Integrate the GUI into KitCommand (opens selector on no args, enforces mid-game selection rules, remove/replace backup kits when switching) and register MenuListener in the main plugin. Add permission speedhg.bypass and update ConnectListener to kick joiners when a game is running unless they have the bypass permission. Remove static playstyle lore from language file (now rendered dynamically), and apply small import/refactor cleanups (use wildcard imports for kit impls, java.util.* replacements).

src/main/resources/plugin.yml

@@ -6,6 +6,11 @@ api-version: '1.21'
 depend:
   - "WorldEdit"
 
+permissions:
+  speedhg.bypass:
+    description: 'Allows joining the server while its running'
+    default: false
+
 commands:
   kit:
     description: 'Select kits via command'