v0.2.0

v0.2.0 — Mojo 1.2 only

Drops Mojo 1.1: a compiled Mojo package loads only in the version that
produced it, so consumers on 1.1 stay on v0.1.3. Built and tested against
1.2.0.dev2026092105.

Since v0.1.3: row-encoded sort keys for fixed-width and string columns
(#108), the scoped worker pool (#103), parallel join output and
partitioned id assembly (#105), and the CSV field-slice decode, bulk byte
copy, UTF-8 narrowing and parallel concat (#107).

Against Polars at 1M rows over that span: sort 6.7x -> 1.7x, join
6.8x -> 4.7x, CSV read 7.8x -> 5.2x.