fix: pre-download pured daemon + start it before purevpn-cli

The purevpn-cli binary hardcodes a wrong S3 path for the daemon download
which returns HTTP 403. The correct URL (from the installer script) is:
  /cross-platform/linux-daemon/1.4.1/pured-linux-x64.gz

purevpn-cli is a client that talks to the pured daemon on :9485.
Pre-download the daemon during Docker build and start it in the entrypoint
before any purevpn-cli invocations.

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

vpn-node/entrypoint.sh

@@ -213,6 +213,16 @@ auto_mode() {
 # ════════════════════════════════════════════════════════════════════════════════
 whitelist_eth0
 
+# ── Start pured daemon ────────────────────────────────────────────────────────
+log "Starting pured daemon …"
+NODE_ENV=production /opt/purevpn-cli/pured-linux-x64 --start &
+# Wait until daemon is listening on :9485 (up to 15s)
+for i in $(seq 1 15); do
+    nc -z 127.0.0.1 9485 2>/dev/null && { log "pured listening on :9485"; break; }
+    sleep 1
+done
+nc -z 127.0.0.1 9485 2>/dev/null || log "WARNING: pured not listening after 15s — continuing anyway"
+
 if [[ "$MANUAL_CONNECT" == "true" ]]; then
     manual_mode
 else