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/rollback-npc/scripts/npc.gd

@@ -0,0 +1,76 @@
+@tool
+extends CharacterBody3D
+
+@export var speed: float = 2.0
+@export var sensor_radius: float = 4.0
+@export var min_radius: float = 1.5
+
+@onready var label := $Label3D as Label3D
+@onready var rbs := $RollbackSynchronizer as RollbackSynchronizer
+
+# Get the gravity from the project settings to be synced with RigidBody nodes.
+var gravity = ProjectSettings.get_setting(&"physics/3d/default_gravity")
+
+func _get_rollback_state_properties() -> Array:
+	return [
+		"position",
+		"velocity"
+	]
+
+func _get_interpolated_properties() -> Array:
+	return [
+		"position"
+	]
+
+func _rollback_tick(dt, _tick, _is_fresh: bool):
+	label.text = "pre" if rbs.is_predicting() else "sim"
+
+	# Add gravity
+	_force_update_is_on_floor()
+	if not is_on_floor():
+		velocity.y -= gravity * dt
+
+	var target_motion := Vector3.ZERO
+	var nearby_player := _find_nearby_player()
+	if nearby_player:
+		target_motion = nearby_player.global_position - global_position
+		target_motion.y = 0.
+
+		target_motion = target_motion.normalized() * speed
+
+	velocity.x = move_toward(velocity.x, target_motion.x, speed / 0.35 * dt)
+	velocity.z = move_toward(velocity.z, target_motion.z, speed / 0.35 * dt)
+
+	# move_and_slide assumes physics delta
+	# multiplying velocity by NetworkTime.physics_factor compensates for it
+	velocity *= NetworkTime.physics_factor
+	move_and_slide()
+	velocity /= NetworkTime.physics_factor
+
+func _find_nearby_player() -> Node3D:
+	var players := get_tree().get_nodes_in_group(&"Players")
+	if players.is_empty():
+		return null
+
+	var sensor_radius_squared := pow(sensor_radius, 2.0)
+	var min_radius_squared := pow(min_radius, 2.0)
+
+	var closest_player: Node3D = null
+	var closest_distance := INF
+	for player in players:
+		var distance := global_position.distance_squared_to(player.global_position)
+
+		if distance >= sensor_radius_squared or distance <= min_radius_squared:
+			continue
+
+		if distance < closest_distance:
+			closest_distance = distance
+			closest_player = player
+
+	return closest_player
+
+func _force_update_is_on_floor():
+	var old_velocity = velocity
+	velocity = Vector3.ZERO
+	move_and_slide()
+	velocity = old_velocity