t_p2: Add team, spawn, and buy-zone system

- team_data.gd: Team enum (SPECTATOR/CT/Terrorist), constants for names,
  colors, starting money, and spawn groups; TeamData resource class
- team_manager.gd: Player-to-team assignment, auto-balancing, score
  tracking; round-independent (persists across rounds)
- spawn_manager.gd: Scans scene for Marker3D nodes in spawn_points_ct
  and spawn_points_t groups; selects valid spawns (farthest from enemies
  with proximity check, fallback to first available)
- buy_zone.gd: Area3D-based trigger zone with team filtering, player
  enter/exit tracking and signals
- test_range.tscn: Added 2 CT spawn markers and 2 T spawn markers with
  appropriate groups

client/assets/maps/test_range/test_range.tscn

@@ -74,13 +74,35 @@ directional_shadow_split_3 = 0.6
 directional_shadow_blend_splits = true
 
 
-; === Spawn Point ===
+; === Spawn Points ===
 
 [node name="SpawnPoint" type="Marker3D" parent="."]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -30, 0.5, 0)
 groups = ["spawn_points"]
 
 
+; === CT Spawn Points (Counter-Terrorist) ===
+
+[node name="CTSpawn_01" type="Marker3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -30, 0.5, -10)
+groups = ["spawn_points_ct"]
+
+[node name="CTSpawn_02" type="Marker3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -25, 0.5, -15)
+groups = ["spawn_points_ct"]
+
+
+; === T Spawn Points (Terrorist) ===
+
+[node name="TSpawn_01" type="Marker3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 25, 0.5, 25)
+groups = ["spawn_points_t"]
+
+[node name="TSpawn_02" type="Marker3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 30, 0.5, 20)
+groups = ["spawn_points_t"]
+
+
 ; === Open Area Floor (80×80) ===
 
 [node name="Floor" type="CSGBox3D" parent="."]