Field registry: search every field, dataset, series and function

The FLDS dictionary: one row per field across the screener catalog, the bulk datasets and their columns, the =KRESMION(entity, path) mnemonics, the curated FRED series, the Excel add-in functions and the data caveats. Each row names its catalog, type or unit, source, the doors that serve it, and a live coverage count of its universe (null where the field has no per-entity universe). q is a case-insensitive token search over id, label, description, source and unit; catalog narrows to one of: screener, bulk, sheet_path, fred, excel, caveat. Fields from sources whose terms do not permit redistribution are not listed (meta.withheld counts them). Descriptive metadata only.