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/data/weapons/awp.tres

@@ -0,0 +1,23 @@
+[gd_resource type="Resource" script_class="WeaponData" load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://examples/multiplayer-fps/scripts/data/weapon_data.gd" id="1"]
+
+[resource]
+script = ExtResource("1")
+weapon_id = 6
+weapon_name = "AWP"
+slot = 2
+damage = 110
+fire_rate = 1.5
+fire_mode = 0
+magazine_size = 10
+reserve_size = 30
+move_speed = 4.0
+recoil_per_shot = 0.0
+recoil_recovery = 0.0
+kill_reward = 50
+armor_penetration = 0.97
+price = 4750
+team = -1
+max_distance = 1000.0
+reload_time = 3.7