Fix headless class_name dependencies

- Replaced TeamData.Team type hints with int in all scripts
- Added explicit preloads for headless mode class resolution
- Created stub LagCompensation and DamageProcessor scripts
- Fixed PluginManager, SpawnManager, EconomyManager, BuyZone,
  RoundManager, BuyMenuHandler, BombObjective class_name references
- Updated server config to match ServerConfig.gd format

Gray screen root cause: server scripts failed to parse in headless
mode due to Godot 4 class_name loading order (Resource after Node),
leaving server_main.gd non-functional — accepted connections but
never spawned players.

server/scripts/zones/buy_zone.gd

@@ -26,6 +26,7 @@
 
 extends Area3D
 class_name BuyZone
+const _td_bz = preload("res://scripts/teams/team_data.gd")
 
 # ---------------------------------------------------------------------------
 # Signals
@@ -44,8 +45,8 @@ signal player_exited_buyzone(player_id: int)
 
 ## Which team(s) can use this buy zone.
 ## Team.COUNTER_TERRORIST = 1, Team.TERRORIST = 2, Team.SPECTATOR = 0.
-## Use the Team enum: TeamData.Team.COUNTER_TERRORIST, etc.
-@export var zone_team: TeamData.Team = TeamData.Team.COUNTER_TERRORIST
+## Use the Team enum: int.COUNTER_TERRORIST, etc.
+@export var zone_team: int = _td_bz.Team.COUNTER_TERRORIST
 
 ## Radius of the buy zone in Godot units (visual hint only; actual collision
 ## shape determines the trigger volume).
@@ -97,7 +98,7 @@ func get_players_in_buyzone() -> Array[int]:
 
 
 ## Check if the given team is allowed to use this buy zone.
-func is_team_allowed(team: TeamData.Team) -> bool:
+func is_team_allowed(team: int) -> bool:
 	if allow_all_teams:
 		return true
 	return team == zone_team