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/server.json.example

@@ -0,0 +1,6 @@
+{
+  "listen": "0.0.0.0:8443",
+  "psk": "REPLACE_WITH_GENERATED_PSK_FROM_gen-key_COMMAND",
+  "max_connections": 1024,
+  "log_level": "info"
+}