v1.2.0

Lucida v1.2.0 — Runway renders images

Runway was video-only here while it sells image generation. It now
renders images with its own two models.

  feat  runway images — gen4_image (from text) and gen4_image_turbo
        (from up to three reference images), a seed, and sixteen pixel
        ratios, where the pair is also the output size. The output carries
        a signed C2PA manifest and no pixel watermark was found.
  feat  `lucida models --provider runway` lists image and video models,
        each half labelled; google shows its Veo aliases the same way.
  fix   runway video refused `--aspect 16:9`. A ratio is now accepted on
        both runway lanes wherever an offered pixel pair has its shape.
  fix   `--provider runway` no longer reaches models Runway resells from
        other companies; they are refused by name.
  fix   `lucida update` recognises a copy cargo installed under
        CARGO_INSTALL_ROOT or install.root, and rebuilds it with cargo
        instead of overwriting it.