fix: swap creation + China npm mirror for 1GB VPS

- Creates 1GB swap file before build (prevents OOM on low-RAM VPS)
- Auto-detects China network block on npmjs.org → switches to npmmirror
- deploy/setup.sh: minimal script for pre-built tarball deployment

install.sh

@@ -32,6 +32,20 @@ bail() { err "Unsupported OS: $OS. Install manually: $1"; exit 1; }
 
 # ── Sudo check ─────────────────────────────────
 sudo -v || (err "sudo required" && exit 1)
+SU() { echo "$SUDO_PASS" | sudo -S "$@" 2>/dev/null || sudo "$@"; }
+
+# ── Swap (prevent OOM on low-RAM VPS) ──────────
+if [ "$(free -m | awk '/^Swap:/{print $2}')" -lt 512 ]; then
+  info "Creating 1GB swap file..."
+  SU dd if=/dev/zero of=/swapfile bs=1M count=1024 status=none
+  SU chmod 600 /swapfile
+  SU mkswap /swapfile >/dev/null
+  SU swapon /swapfile
+  if ! grep -q /swapfile /etc/fstab 2>/dev/null; then
+    echo '/swapfile none swap sw 0 0' | SU tee -a /etc/fstab >/dev/null
+  fi
+  log "Swap created (1GB)"
+fi
 
 # ── git + curl ─────────────────────────────────
 for cmd in git curl; do
@@ -84,6 +98,13 @@ else
   log "Node.js $(node -v) already installed"
 fi
 
+# ── npm mirror (auto-detect China) ──────────────
+if curl -sI --connect-timeout 3 https://registry.npmjs.org/ 2>&1 | grep -q "timed out\|Connection refused\|Could not resolve\|Network"; then
+  info "npmjs.org unreachable — switching to China mirror"
+  npm config set registry https://registry.npmmirror.com
+  log "Using npmmirror.com"
+fi
+
 # ── Caddy ────────────────────────────────────────
 if ! command -v caddy &>/dev/null; then
   info "Installing Caddy..."