bun's pgdialect overrides Field.Scan/Append with its own slice-only array
handling whenever the tag's type: value ends in "[]", clobbering the
sql.Scanner/driver.Valuer implemented on SqlXxxArray wrapper types and
causing "bun: Scan(unsupported sqltypes.SqlStringArray)" at query time.
Emit the underscore-prefixed internal type name (e.g. _text) instead,
which is DDL-valid but doesn't end in "[]" so bun leaves our scanner alone.