Implement a CSIP-Aus dynamic operating envelope (DOE) client that receives per-interval export/import limits from an Australian DNSP IEEE 2030.5 server

Steps

1. Authenticate with the DNSP's IEEE 2030.5 server using mutual TLS with a certificate issued by the DNSP's CA; discover the DER Program list at /dcap -> /sdev -> /derp
2. Subscribe to DERControl notifications using the IEEE 2030.5 notification/subscription mechanism (POST to /sub) to receive push updates when a new DOE interval is published
3. Parse the received DERControlBase: read opModExpLimW for the export limit in watts and opModImpLimW for the import limit; both are per-phase signed integers per the CSIP-Aus extension to IEEE 2030.5-2018
4. Apply the export/import limits to the behind-the-meter energy management controller; log each limit change with epoch timestamp and MRID for AEMO settlement reconciliation
5. Report compliance by POSTing a MirroredUsagePoint reading (real power in watts) to /mup at the interval cadence specified in the server's MirroredUsagePoint configuration
6. Handle the 'no active DOE' case: if the server returns an empty DERControl list, revert to the static maximum export capacity from the Connection Agreement