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/forest-brawl/scripts/effects/repulse-effect.gd

@@ -0,0 +1,25 @@
+extends Effect
+
+@export var area: Area3D
+@export var strength: float = 4.0
+
+func _rollback_tick(tick):
+	super._rollback_tick(tick)
+
+	if not is_active():
+		return
+
+	for body in area.get_overlapping_bodies():
+		if not body is BrawlerController or body == get_parent_node_3d():
+			continue
+		
+		var brawler := body as BrawlerController
+		var diff: Vector3 = brawler.global_position - global_position
+		var f = clampf(1.0 / (1.0 + diff.length_squared()), 0.0, 1.0)
+		f = clampf(1. - diff.length_squared() / 16., 0., 1.)
+		diff.y = max(0, diff.y)
+		var motion = diff.normalized() * strength * f * NetworkTime.ticktime
+		brawler.shove(motion)
+
+		brawler.register_hit(get_parent_node_3d())
+		NetworkRollback.mutate(brawler)