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>

docs/external-tutorials.md

@@ -0,0 +1,32 @@
+# External tutorials
+
+While these docs aim to cover everything netfox-related, we are happy to be
+promoting other creators who also create content that helps understanding
+netfox.
+
+## BatteryAcidDev
+
+In-depth tutorials explaining networking from the basics. Excellent content
+both for newcomers and seasoned developers. Make sure to check the YouTube
+channel as well as these videos!
+
+- [Godot Multiplayer Lag Compensation with Netfox](https://youtu.be/GqHTNmRspjU?si=--fKtAOvJiYd5RTd)
+- [Start Your Multiplayer Game with this Template](https://youtu.be/AplKwFtBMjU?si=LBwW4X5D_A4gL33U)
+- [Complete Game Walkthrough](https://youtu.be/tWLZNCJISYU?si=1ewd1fgd5vx-3HI1)
+- [Run Your Own P2P Server with Noray!](https://youtu.be/9pEBq6hLCzQ?si=OlyK-NXyxsnJ2A8A)
+
+[:simple-youtube: YouTube](https://www.youtube.com/@BatteryAcidDev/) |
+[:simple-discord: Discord](https://discord.gg/psjbBDvNBK)
+
+## Your content here!
+
+Are you making a video about netfox? A tutorial series? A blog post? Something
+else?
+
+Let us know, we'd love to feature it! Reach out on [Github discussions], on
+[Discord], or in the comments at the bottom of this page.
+
+
+[Github discussions]: https://github.com/foxssake/netfox/discussions/
+[Discord]: https://discord.gg/xWGh4GskG5
+