FitResultExtractor

Converts the live, non-serializable products of a continuous fit (PDFModeler + PDFModelingResults) into the serializable FitResultData graph. This is the orchestration layer's core translation step: it is the one place that reads the engine's live objects and emits wire-safe DTOs, identical whether the engine is co-located or remote.

MODA results are sourced from the model's own record producers (metricData(), alternativeScoreData(), alternativeValueData(), alternativeRankFrequencyData()) rather than by walking the model; each producer record's database id and repeated model name are dropped on the mapping. No plot data is produced — a client rebuilds plots from its own data plus the returned fitted distribution.