Online Counter 1.0.0

I changed a few things that I think would benefit an update in the source code.

What Changed

• Made the UI text configurable via format strings
  • Added FormatCountText(int count) so "Text Count" in config can be something like "{0}/100" or "Online: {0}"
• Added permission-driven behavior
  • onlinecounter.noui → player won’t see the UI
  • onlinecounter.dontcountme → player won’t be included in the online count  
  • Introduced ShouldShowUI() / ShouldCountOnline() helpers to keep this logic clean.
• Improved counting + UI refresh flow
  • Recounts on startup (`CountOnlinePlayers()`)
  • Adjusts `_onlineCount` on connect/disconnect with safety (Mathf.Max(0, ...))
  • Uses `NextTick(UpdateUIForAllPlayers)` on disconnect to avoid timing issues
  • Rebuilds the UI for all active players via UpdateUIForAllPlayers() / ShowUI()

OnlineCounter.cs