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/multiplayer-fps/scripts/bombsite.gd

@@ -0,0 +1,26 @@
+extends Area3D
+class_name Bombsite
+
+@export var site_name: String = "A"
+
+func _ready():
+	monitoring = true
+	monitorable = true
+	add_to_group("bombsite")
+
+	# Create default collision shape if none assigned
+	var has_shape := false
+	for child in get_children():
+		if child is CollisionShape3D and child.shape != null:
+			has_shape = true
+			break
+	if not has_shape:
+		var shape := BoxShape3D.new()
+		shape.size = Vector3(8, 4, 8)
+		var col := CollisionShape3D.new()
+		col.shape = shape
+		add_child(col)
+
+func is_player_inside(player: CharacterBody3D) -> bool:
+	var overlapping := get_overlapping_bodies()
+	return player in overlapping