v3.0.1

Fixed

• The console no longer opens a seam under the code block. The strip took 0.25rem
  of padding on all four sides, and the top quarter of that landed exactly on the join
  the 3.0.0 layout works to hide — no top border, shared corners, two boxes meant to read
  as one — so a gap appeared right where the block was supposed to run into the strip. It
  is padding: 0 0 0.25rem now; the space below the last line stays.

  CSS an author may be targeting: code-preview .code-preview-console. A sheet that
  restores symmetric padding gets the seam back. The asymmetry is now stated in the
  comment above the rule so it does not read as an oversight worth tidying.

• Upgrading no longer shifts the page twice while the manifest loads. The pre-upgrade
  reservation counted the code strip and the options panel, then upgrade dropped it whole
  — but with manifest both boxes wait on a fetch, so the page rose by their height and
  came back down when they landed. Measured on a consumer's docs: upgrade at 224ms,
  arrival at 274ms, a layout shift each way, on every load. Three CSS rules now carry the
  reservation across the gap: the strip's row is held as top margin on the first pane
  until the tablist exists, the tab="options" panel's box is held by an ::after until
  the panel exists, and an editable block wears --code-preview-hint-space from the
  start instead of growing by it when the editor attaches. The costs run the honest way:
  a page that names a manifest and never loads the options bundle keeps the held strip
  row for good, and a pane read-only by fence word wears the editor padding for the wait
  and gives it back.

Full Changelog: v3.0.0...v3.0.1