Add optional broker_ip and broker_tls_name config fields so the TCP
dial target can be a scoped IPv6 address (fe80::...%eth0) while TLS
certificate verification still uses the broker hostname.
Also revert to alpine/static build; CGO was not needed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Subscribes to Eastron SDM630 power meter data via MQTT broker,
decodes Modbus RTU frames, and writes readings to InfluxDB.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
