ax-normalize — any corpus → one [RecordSet]

The article's normalization promise: "given any corpus of information regardless of its format, we'll normalize it." This crate maps recognized text formats (CSV, TSV, NDJSON, JSON) onto the engine-independent [RecordSet] from ax-core. Binary columnar formats (Parquet, Arrow IPC) land behind this same boundary in the Polars-backed slice — detectors never see the difference.

Normalization is deterministic: column order is stable (header order for tabular input, sorted key-union for JSON), and absence is explicit — a key missing from one JSON row becomes [ax_core::Value::Null], never a guess.