Beztrace 0.2.1 — verified fitting and compatible smoothing

Beztrace 0.2.1 adds independently verified hybrid fitting and optional joint
smoothing to the standalone master-matching engine.

• Levien-style cubic proposals run first, with refined least-squares fallback.
• Target-only smoothing shares the original fit-error budget and preserves the
  reference, on-curves, node counts/order/types and flags. Unsafe repairs refuse
  without relaxing the limit. Graph selection remains deferred.
• JSON schema v1 and pathDataVersion 2 remain unchanged. The engine runs without
  Glyphs, Python or external runtime dependencies.

The distribution is universal arm64 + x86_64, Developer ID signed and
Apple-notarized. The PKG includes a stapled ticket. Verify SHA256SUMS before use.
Native Intel execution is untested and explicitly owner-waived for 0.2.1;
x86_64/Rosetta comparisons are separate evidence.

The 18 controlled pair cases and 12 smoothing cases retain exact accepted
geometry, reports, original-source bounds and refusal thresholds after signing.
Signed installation, rollback to published 0.2.0, owned removal and reinstallation pass in the Gatekeeper-enabled macOS 14.6.1 arm64 VM. See the attached qualification receipt.

The separately released Glyphs companion 0.2.0/build 25 supports this engine. If using companion
0.1.0/build 15, retain its supported 0.1.1 engine and run 0.2.1 from the standalone
ZIP separately. Installing this CLI does not upgrade a companion.

Published 0.2.0 and earlier releases retain their original tags and asset bytes.