v4.1.2

Release v4.1.2 — DS meta refresh 0.58 → 0.59

Content-only refresh. Single-minor DS delta = PATCH per convention.
Bumps @lando-labs/lando-ds-meta from ^0.58.0 to ^0.59.0.

DS v0.59.0 delivers:

• CSS layer-order contract fix: @layer app overrides beat DS component
  styles reliably now, no primer import needed.
• ThemeScope re-derives tonal ramps + interaction states via color-mix()
  on the scope element; also fixes system-mode SSR hydration mismatch
  for scopes without explicit mode.
• Button primary WCAG AA contrast fix for midnight/sunset/forest/rose
  presets via new onPrimary field.
• SegmentedControl sliding indicator first-paint fix.

No tool contract changes.