The TOML config path accepted out-of-range gateway.port values even though the documented and JSON-stdin validation surface requires 1-65535. This change brings TOML loading into parity and adds coverage for the repository’s primary example config.

• Config validation

  • Reject explicitly configured TOML gateway.port values outside 1-65535 during LoadFromFile
  • Gate the check on md.IsDefined("gateway", "port") so defaulting behavior remains unchanged when the key is omitted

• Regression coverage

  • Add a focused test for invalid TOML input with port = 99999
  • Add a load test for config.example.toml to catch parser/example drift

• Behavior

  • Explicit invalid TOML now fails early instead of being silently accepted

if md.IsDefined("gateway", "port") {
	if err := PortRange(cfg.Gateway.Port, "gateway.port"); err != nil {
		return nil, err
	}
}