Method GeneratePvtCte(IReadOnlyList<FieldInfo>, string, string, string?)

Generates two-level CTE with MAX(CASE WHEN) optimization.
Level 1 (raw_values): Aggregates values with MAX(CASE WHEN v._id_structure = X THEN v.column END)
Level 2 (pvt_cte): Applies filters on aliased columns.
Uses STRING_AGG for array fields.

public PvtSqlGenerator.PvtCteResult GeneratePvtCte(IReadOnlyList<FieldInfo> fields, string whereCondition, string schemeIdParam, string? additionalObjectFilter = null)