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>

addons/netfox.extras/physics/rapier_driver_3d.gd.off

@@ -2,17 +2,36 @@ extends PhysicsDriver
 
 class_name RapierDriver3D
 
+var _state: StateManager3D
+
+var _stored_states: int = 0
+
+
 func _init_physics_space() -> void:
 	physics_space = get_viewport().world_3d.space
 	PhysicsServer3D.space_set_active(physics_space, false)
 
+	_state = StateManager3D.new()
+	_state.root_node = self
+	_state.set_max_cache_length(ProjectSettings.get_setting("netfox/rollback/history_limit", 64))
+	_state.set_rolling_cache(true)
+	add_child(_state)
+
+
 func _physics_step(delta) -> void:
 	RapierPhysicsServer3D.space_step(physics_space, delta)
 	RapierPhysicsServer3D.space_flush_queries(physics_space)
-	
-func _snapshot_space(tick: int) -> void:
-	snapshots[tick] = RapierPhysicsServer3D.export_binary(physics_space)
 
-func _rollback_space(tick) -> void:
-	if snapshots.has(tick):
-		RapierPhysicsServer3D.import_binary(physics_space, snapshots[tick])
+
+func _snapshot_space(tick: int) -> void:
+	_state.cache_state(physics_space, tick)
+
+
+func _rollback_space(tick: int) -> void:
+	# With rolling cache, tick states are ordered by age with the newest at 0
+	var offset = NetworkTime.tick - tick
+	if (offset >= _stored_states):
+		return
+
+	_stored_states = min(_stored_states + 1, _state.max_cache_length)
+	_state.load_cached_state(physics_space, offset)