Add tablist manager and Volcano rank provider

Introduce a TablistManager to manage per-player scoreboard teams, tab header/footer and periodic updates; uses a ServerRankProvider abstraction. Add DefaultServerRankProvider and VolcanoServerRankProvider (uses CoreAPI) in ServerRankProvider.kt. Wire TablistManager into SpeedHG: initialize in onLoad, update on join, and shutdown on disable. Add local VolcanoAPI.jar as compileOnly dependency and declare Volcano as a plugin dependency in plugin.yml.

src/main/resources/plugin.yml

@@ -6,6 +6,7 @@ api-version: '1.21'
 depend:
   - "WorldEdit"
   - "Apollo-Bukkit"
+  - "Volcano"
 
 permissions:
   speedhg.bypass: