stdocs v0.6.8

Changed

• Updated the bundled Scalar UI (ui/scalar and ui/scalaremb) to
  @scalar/api-reference 1.60.0 — an additive minor (a content.start
  plugin slot and an opt-in sidebar for plugin views) plus a handful of
  rendering fixes. The standalone build and the data-url bootstrap the
  UIs rely on are unchanged, so the docs page and its CSP are untouched;
  the CDN sha384 SRI and the vendored air-gapped bundle are re-pinned to
  the new bytes, verified byte-identical between the npm tarball and the
  pinned jsDelivr URL.

Fixed

• The README described the built-in docs page as ~1.6 KB — accurate at
  v0.1.0, but it has grown to ~10 KB across the v0.6.x additions (the
  security headers, the dismissable notice, method badges, and the
  expandable operations). Corrected the figure and aligned it with the
  source. Also tidied a couple of stale doc comments left over from
  older "Tier" terminology.