feat: Universal Linux build + redesigned ostp-guard

- Build static musl binaries (work on any Linux distro)
- Redesign ostp-guard with weighted scoring system (threshold: 4 points)
  - HIGH (2pts): Analysis tools (gdb/ida/ghidra), sandbox artifacts
  - MEDIUM (1pt): Low resources (<1GB RAM), suspicious env vars
- Production VPS safe (1-2 points), sandbox blocked (4+ points)
- Anti-debug: Windows (IsDebuggerPresent), Linux (/proc/self/status)
- Deployment packages for Linux + Windows with SHA256 checksums

dist/linux-amd64/ostp-server.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=OSTP Stealth VPN Server
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/etc/ostp
+ExecStart=/usr/local/bin/ostp-server -c /etc/ostp/server.json
+Restart=on-failure
+RestartSec=10s
+LimitNOFILE=65536
+
+# Security hardening
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/etc/ostp
+
+[Install]
+WantedBy=multi-user.target