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>

test/netfox.internals/set.test.gd

@@ -0,0 +1,122 @@
+extends VestTest
+
+func get_suite_name() -> String:
+	return "Set"
+
+#region add() + values()
+func test_add_should_persist() -> void:
+	# Given
+	var set := _Set.new()
+	var expected := [2, "foo"]
+
+	# When
+	set.add(2)
+	set.add("foo")
+
+	# Then
+	expect_equal(set.values(), expected)
+	expect_equal(set.size(), 2)
+	expect(not set.is_empty())
+
+#endregion
+
+#region has()
+func test_should_have_known_items() -> void:
+	# Given
+	var set := _Set.new()
+	set.add(2)
+	
+	# When + Then
+	expect(set.has(2))
+
+func test_should_not_have_unknown_items() -> void:
+	# Given
+	var set := _Set.new()
+	set.add(2)
+	
+	# When + Then
+	expect_not(set.has("Foo"))
+
+#endregion
+
+#region size() + is_empty()
+func test_new_set_should_be_empty() -> void:
+	# Given
+	var set := _Set.new()
+	
+	# Then
+	expect(set.is_empty())
+	expect_equal(set.size(), 0)
+
+func test_set_should_not_be_empty() -> void:
+	# Given
+	var set := _Set.new()
+	
+	# When
+	set.add("foo")
+	set.add("bar")
+
+	# Then
+	expect_not(set.is_empty())
+	expect_equal(set.size(), 2)
+#endregion
+
+#region erase() + clear()
+func test_erase_should_remove() -> void:
+	# Given
+	var set := _Set.of(["foo", "bar", "quix"])
+	var expected = ["foo", "quix"]
+
+	# When
+	set.erase("bar")
+
+	# Then
+	expect_equal(set.values(), expected)
+
+func test_clear_should_make_empty() -> void:
+	# Given
+	var set := _Set.of(["foo", "bar", "quix"])
+
+	# When
+	set.clear()
+
+	# Then
+	expect_empty(set)
+#endregion
+
+#region iteration
+func test_empty_should_not_be_iterable() -> void:
+	# Given
+	var set := _Set.new()
+
+	# When + then
+	expect_not(set._can_iterate(), "Set shouldn't be iterable")
+
+func test_should_be_iterable() -> void:
+	# Given
+	var set := _Set.of([2, "Foo"])
+
+	# When + then
+	expect(set._can_iterate(), "Set should be iterable")
+
+func test_iterate_should_yield_values() -> void:
+	# Given
+	var set := _Set.of([1, 2, "Foo", {}])
+	var expected := [1, 2, "Foo", {}]
+	var iterated := []
+
+	# When
+	for item in set:
+		iterated.append(item)
+
+	# Then
+	expect_equal(iterated, expected)
+#endregion
+
+func test_min_max() -> void:
+	# Given
+	var set := _Set.of([2, 1, 3])
+	
+	# When + Then
+	expect_equal(set.min(), 1)
+	expect_equal(set.max(), 3)