Add ranking system and /ranking command

Introduce a ranking system: add Rank enum and RankingManager enhancements (isRankingEnabled toggle, getRank(), RR change handling, rank-up/down detection and player notifications with titles/sounds). Add a new /ranking admin command (toggle, status, rank) with tab completion and register it in plugin startup. Surface player rank on the scoreboard (ScoreboardManager) and add related language entries and plugin.yml permission/command metadata. Logging updated to include ranked state.

src/main/resources/plugin.yml

@@ -13,6 +13,9 @@ permissions:
   speedhg.admin.timer:
     description: 'Change the current game time'
     default: false
+  speedhg.admin.ranking:
+    description: 'Manage the ranking system (toggle unranked mode, inspect ranks)'
+    default: false
 
 commands:
   kit:
@@ -24,4 +27,8 @@ commands:
   timer:
     description: 'Change the current game time (Admin Command)'
     usage: '/timer <seconds>'
-    permission: speedhg.admin.timer
+    permission: speedhg.admin.timer
+  ranking:
+    description: 'Manage the SpeedHG ranking system'
+    usage: '/ranking <toggle|status|rank [player]>'
+    permission: speedhg.admin.ranking