fix(deploy): use '--' separator so Godot passes --server to user args

Godot reads get_cmdline_user_args() which only contains args after '--'.
Without the separator, NetworkManager never saw --server and the
ENetMultiplayerPeer never bound UDP 7777.

Verified on 192.168.0.89: udp/7777 now listening.

builds/run_server.sh

@@ -6,4 +6,4 @@ PORT="${1:-7777}"
 BINARY_DIR="$(dirname "$(readlink -f "$0")")"
 cd "$BINARY_DIR"
 
-exec ./DauphinCraftServer.x86_64 --server --port "$PORT" --headless
+exec ./DauphinCraftServer.x86_64 --headless -- --server --port "$PORT"

deploy/dauphincraft.service

@@ -7,7 +7,7 @@ Type=simple
 User=dauphin
 Group=dauphin
 WorkingDirectory=/opt/dauphincraft
-ExecStart=/opt/dauphincraft/DauphinCraftServer.x86_64 --server --port 7777 --headless
+ExecStart=/opt/dauphincraft/DauphinCraftServer.x86_64 --headless -- --server --port 7777
 Restart=always
 RestartSec=5
 StandardOutput=append:/var/log/dauphincraft.log