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-fps/ui/fps-hud.gd

@@ -0,0 +1,26 @@
+extends Control
+
+@onready var health_bar := $ProgressBar as ProgressBar
+
+var player: ExampleRollbackFPS.Player
+
+static var _inst
+
+static func set_player(p_player: ExampleRollbackFPS.Player) -> void:
+	if not _inst: return
+
+	_inst.player = p_player
+	_inst.visible = true
+	_inst.set_process(true)
+
+func _ready():
+	visible = false
+	set_process(false)
+	_inst = self
+
+func _process(_dt) -> void:
+	if not is_instance_valid(player):
+		set_process(false)
+		return
+
+	health_bar.value = player.health

examples/rollback-fps/ui/fps-hud.gd.uid

@@ -0,0 +1 @@
+uid://cycmne5n6ov65

examples/rollback-fps/ui/fps-hud.tscn

@@ -0,0 +1,53 @@
+[gd_scene load_steps=4 format=3 uid="uid://cdue87s0gmc4d"]
+
+[ext_resource type="Script" path="res://examples/rollback-fps/ui/fps-hud.gd" id="1_gc5cb"]
+
+[sub_resource type="Gradient" id="Gradient_3rjdk"]
+offsets = PackedFloat32Array(0.962667, 1)
+colors = PackedColorArray(1, 1, 1, 1, 1, 1, 1, 0)
+
+[sub_resource type="GradientTexture2D" id="GradientTexture2D_dsv61"]
+gradient = SubResource("Gradient_3rjdk")
+width = 8
+height = 8
+fill = 1
+fill_from = Vector2(0.5, 0.5)
+fill_to = Vector2(1, 0.5)
+metadata/_snap_enabled = true
+
+[node name="fps-hud" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_gc5cb")
+
+[node name="ProgressBar" type="ProgressBar" parent="."]
+custom_minimum_size = Vector2(128, 0)
+layout_mode = 1
+anchors_preset = 2
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_top = -27.0
+offset_right = 128.0
+grow_vertical = 0
+
+[node name="TextureRect" type="TextureRect" parent="."]
+custom_minimum_size = Vector2(8, 8)
+layout_mode = 1
+anchors_preset = 8
+anchor_left = 0.5
+anchor_top = 0.5
+anchor_right = 0.5
+anchor_bottom = 0.5
+offset_left = -135.0
+offset_top = -4.0
+offset_right = 135.0
+offset_bottom = 4.0
+grow_horizontal = 2
+grow_vertical = 2
+texture = SubResource("GradientTexture2D_dsv61")
+expand_mode = 3
+stretch_mode = 5