Function format_cell_for_field 

pub fn format_cell_for_field(
    value: &Value,
    field: &FieldDef,
    tech: Option<&RowTechMap>,
) -> FormattedCell

Formats a cell using FieldDef metadata and optional technical companions.

Companion map enables Python parity for recommendation (Rec.{name}) and for ADX / AO / Bollinger computed_recommendation columns.