operator [] method
The key with this catalog/key id, or null.
Indexed on the first lookup, because the reader's whole job is a join: every caller walks its own catalog and probes this once per key. A scan made that quadratic, and quietly: the panel's table cost 5ms a rebuild before an export existed and 324ms after one, at 2000 keys — and the studio rebuilds it whenever any plugin says anything at all.
Implementation
ExportedKey? operator [](String id) => _indexOf(this)[id];