feat: crypto library, Nexus HTTP server, JWT CLI, Boko web framework

- lib/crypto/: 9-module crypto library (Hash, HMAC, Base64/URL, Random, AES, RSA, ECDSA, Ed25519, JWT)
- rt/runtime.c: +346 lines OpenSSL crypto primitives (SHA-1/384/512, HMAC, Base64URL, AES-CBC/GCM, RSA, ECDSA, Ed25519)
- apps/nexus/: multi-threaded HTTP/1.1 + HTTP/2 detect + WebSocket server
- apps/jwt-pitbul/: JWT CLI tool (sign, verify, decode, keygen)
- apps/boko-framework/: FastAPI-inspired async web framework
- test_crypto/: crypto library test suite (23 tests)

apps/boko-framework/run_check.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+cd /home/ziko/z-git/bux/bux/apps/boko-framework
+
+echo "=== CHECK ==="
+../../buxc check 2>&1
+echo "CHECK_EXIT=$?"
+
+echo ""
+echo "=== BUILD ==="
+../../buxc build 2>&1
+echo "BUILD_EXIT=$?"
+
+echo ""
+echo "=== FILES ==="
+find . -type f -newer bux.toml 2>/dev/null | head -30
+echo ""
+echo "=== BINARY SEARCH ==="
+file boko-framework 2>/dev/null || echo "no boko-framework"
+ls -la build/ 2>/dev/null || echo "no build dir"