Fresh start: replace with naxIO/netfox-cs-sample foundation

Complete replacement of the tactical-shooter project with the
netfox-cs-sample (MIT) — a CS 1.6 inspired multiplayer FPS built
with Godot 4 and netfox.

## What's new
- Full CS-style gameplay: teams (T/CT), rounds, economy, buy menu
- 6 weapons: Knife, Glock, USP, AK-47, M4A1, AWP
- Bomb plant/defuse with 2 bombsites
- Flashbang & smoke grenades
- Proper netfox rollback netcode at 64 tick
- Network popup UI for host/join
- HUD, crosshair, round timer, scoreboard
- All netfox singletons registered as autoloads (works in exported builds)

## Architecture
- Listen-server (host from client, no dedicated server binary)
- Multiplayer-fps game lives at examples/multiplayer-fps/
- Netfox addons registered as autoloads for exported build compat
- Godot 4.7 with Forward+ renderer

## Removed
- Old headless-server architecture (client_main, server_main, player.gd, etc.)
- Custom netfox bootstrap with ENet fallback
- Old ChaffGames FPS template (2,420 lines, 844 KB)
- SimulationServer GDExtension stub
- Godot-jolt physics (netfox sample uses default Godot physics)
- Duplicate weapon_data.gd, anti_cheat.gd, round_manager.gd, etc.
- Server browser API Python venv (87 MB)
- test_range map and modular assets

## Preserved
- Git history
- Server config at config/default_server_config.cfg
- Windows export preset
- Build directory (gitignored)

Co-authored-by: naxIO <naxIO@users.noreply.github.com>

examples/shared/scenes/environment.tscn

@@ -0,0 +1,22 @@
+[gd_scene load_steps=4 format=3 uid="uid://cncdbq72u50j3"]
+
+[sub_resource type="ProceduralSkyMaterial" id="ProceduralSkyMaterial_bioft"]
+
+[sub_resource type="Sky" id="Sky_n7qj2"]
+sky_material = SubResource("ProceduralSkyMaterial_bioft")
+
+[sub_resource type="Environment" id="Environment_ge6yj"]
+background_mode = 2
+sky = SubResource("Sky_n7qj2")
+
+[node name="Environment" type="Node"]
+
+[node name="DirectionalLight3D" type="DirectionalLight3D" parent="."]
+transform = Transform3D(0.5, 0.612372, -0.612372, 0, 0.707107, 0.707107, 0.866025, -0.353553, 0.353553, -6.7361, 8.77817, 3.88909)
+shadow_enabled = true
+
+[node name="Camera3D" type="Camera3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 0.5, 0.866025, 0, -0.866025, 0.5, 0, 14.3564, 8.86602)
+
+[node name="WorldEnvironment" type="WorldEnvironment" parent="."]
+environment = SubResource("Environment_ge6yj")

examples/shared/scenes/map-square.tscn

@@ -0,0 +1,39 @@
+[gd_scene format=3 uid="uid://cngy6hs8ohodj"]
+
+[node name="Square Map" type="Node3D"]
+
+[node name="CSGCombiner3D" type="CSGCombiner3D" parent="."]
+use_collision = true
+collision_layer = 2
+
+[node name="CSGFloor" type="CSGBox3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, -0.25, 0)
+size = Vector3(16, 0.5, 16)
+
+[node name="CSGWall" type="CSGBox3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 8)
+size = Vector3(16, 2, 1)
+
+[node name="CSGWall2" type="CSGBox3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, -8)
+size = Vector3(16, 2, 1)
+
+[node name="CSGWall3" type="CSGBox3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 8, 1, 0)
+size = Vector3(1, 2, 16)
+
+[node name="CSGWall4" type="CSGBox3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -8, 1, 0)
+size = Vector3(1, 2, 16)
+
+[node name="CSGCorner" type="CSGCylinder3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 8, 1, 8)
+
+[node name="CSGCorner2" type="CSGCylinder3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 8, 1, -8)
+
+[node name="CSGCorner3" type="CSGCylinder3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -8, 1, -8)
+
+[node name="CSGCorner4" type="CSGCylinder3D" parent="CSGCombiner3D"]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -8, 1, 8)