Fix compilation warnings and namespace issue

Fixed issues:
1. Added missing using directive for KCM.Packets namespace
   - Fixes ShowModal class not found error in Main.cs

2. Removed unused 'callTree' variable (Main.cs:460)
   - Variable was defined but never used

3. Removed unused 'awake' field (ServerLobbyScript.cs:63)
   - Field was assigned but never used

All compilation warnings resolved.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

ServerLobby/ServerLobbyScript.cs

@@ -60,8 +60,6 @@ namespace KCM
             Falle
         }
 
-        bool awake = false;
-
         public void Start()
         {
             Main.helper.Log("ServerLobby start called");