[bug] forecast value 0.0 silently omitted from ConfigMap due to omitempty

[amellier]

Summary

EmissionsDataDto.Value is declared as float64 with json:"value,omitempty". In Go, omitempty on a numeric type omits the field when it equals the zero value (0.0). When a data provider returns 0.0 (e.g. during a WattTime outage), the field is silently dropped from the ConfigMap's binary data field.

Consumers reading the ConfigMap cannot distinguish "missing data" from a legitimate zero-intensity reading.

Steps to reproduce

1. WattTime returns value: 0.0 from /v3/forecast
2. Carbon Aware SDK passes it through unchanged
3. The Go client decodes 0.0 into Value float64
4. On re-encode with omitempty, the value key is absent from the ConfigMap binary data

{ "location": "CAISO_NORTH", "timestamp": "2026-04-23T16:25:00Z", "duration": 5 }

The value field is missing entirely rather than being 0 or null.

Suggested fix

Change Value float64 to Value *float64 in pkg/sdk/client/model_emissions_data_dto.go so that null (truly missing) is distinguishable from 0.0. Note: this file is swagger-generated — the same fix should be proposed upstream to the Carbon Aware SDK.