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/scripts/simple-time-display.gd

@@ -0,0 +1,21 @@
+extends Label
+
+func _ready():
+	NetworkTime.on_tick.connect(_tick)
+
+func _tick(_delta: float, _tick: int):
+	text = "Time: %.2f at tick #%d" % [NetworkTime.time, NetworkTime.tick]
+
+	if not get_tree().get_multiplayer().is_server():
+		# Grab latency to server and display
+		var enet = get_tree().get_multiplayer().multiplayer_peer as ENetMultiplayerPeer
+		if enet == null:
+			return
+			
+		var server = enet.get_peer(1)
+		var last_rtt = server.get_statistic(ENetPacketPeer.PEER_LAST_ROUND_TRIP_TIME)
+		var last_variance = server.get_statistic(ENetPacketPeer.PEER_LAST_ROUND_TRIP_TIME_VARIANCE)
+		var mean_rtt = server.get_statistic(ENetPacketPeer.PEER_ROUND_TRIP_TIME)
+		var mean_variance = server.get_statistic(ENetPacketPeer.PEER_ROUND_TRIP_TIME_VARIANCE)
+
+		text += "\nLast RTT: %s +/- %s\nMean RTT: %s +/- %s" % [last_rtt, last_variance, mean_rtt, mean_variance]