build: Linux dedicated server preset + deploy package (systemd + install script)

- export_presets.cfg: ajout preset.1 Linux Server (dedicated_server=true, embed_pck=true, x86_64)
- builds/DauphinCraftServer.x86_64: binaire serveur Linux 76MB
- builds/run_server.sh: launcher avec port configurable
- deploy/: dauphincraft.service (systemd) + install.sh (VM setup)
- deploy_package/: tarball + scripts prêts à transférer sur VM
- Rebuild client Windows inclus (DauphinCraft.exe 100MB, exit 0)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

deploy_package/dauphincraft.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=DauphinCraft Dedicated Server
+After=network.target
+
+[Service]
+Type=simple
+User=dauphin
+Group=dauphin
+WorkingDirectory=/opt/dauphincraft
+ExecStart=/opt/dauphincraft/DauphinCraftServer.x86_64 --server --port 7777 --headless
+Restart=always
+RestartSec=5
+StandardOutput=append:/var/log/dauphincraft.log
+StandardError=append:/var/log/dauphincraft.log
+
+[Install]
+WantedBy=multi-user.target

deploy_package/install.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# À exécuter sur la VM cible en root
+set -e
+mkdir -p /opt/dauphincraft
+cp DauphinCraftServer.x86_64 /opt/dauphincraft/
+cp run_server.sh /opt/dauphincraft/
+chmod +x /opt/dauphincraft/DauphinCraftServer.x86_64 /opt/dauphincraft/run_server.sh
+useradd -r -s /bin/false dauphin 2>/dev/null || true
+chown -R dauphin:dauphin /opt/dauphincraft
+cp dauphincraft.service /etc/systemd/system/
+touch /var/log/dauphincraft.log
+chown dauphin:dauphin /var/log/dauphincraft.log
+systemctl daemon-reload
+systemctl enable --now dauphincraft.service
+sleep 2
+systemctl status dauphincraft.service --no-pager
+ufw allow 7777/udp 2>/dev/null || iptables -A INPUT -p udp --dport 7777 -j ACCEPT 2>/dev/null || true
+echo "DauphinCraft Server installé. Port UDP 7777 ouvert."