feat(redis): add configurable TLS for Redis connections

feat(redis): add configurable TLS for Redis connections

- Add TLS options to Redis config schema (ssl, no_ssl_verify, ssl_ca, ssl_ca_dir, ssl_cert, ssl_key, sni)
- Thread TLS options through lua_redis and request helpers
- Implement TLS handshake in redis pool using hiredis SSL (redisCreateSSLContextWithOptions + redisInitiateSSLWithContext)
- Keep plain connections default and support Unix sockets
- Add unit test to validate TLS options propagation (test/lua/unit/redis_tls.lua)

Tested against local TLS Redis on localhost:6379 (PING returns PONG).