v0.2.0

Added

• An options panel, as a third bundle you opt into —
  dist/code-preview-options.min.js, 7KB, carrying no copy of the element. A manifest
  attribute pointing at a
  custom-elements.json turns on
  a second tab beside the code, with controls generated from it: attributes[] become
  attribute knobs, cssProperties[] become custom-property knobs, and each control's kind
  comes from the type or Houdini syntax the manifest already declares.

  <script src="dist/code-preview-options.min.js"></script>
  
  <code-preview manifest="dist/custom-elements.json" tab="options"> … </code-preview>

  The two halves of the panel write to two different places, which is the one real design
  decision in it. An attribute belongs to an element in the sample, so its knob rewrites
  the code block — spliced into the opening tag with a regex rather than parsed and
  re-serialized, because on a documentation page the markup is the documentation and
  reformatting it on the first knob turn is not acceptable. Edit it back by hand and the
  controls re-read the source next time the tab is opened. A custom property is not part
  of the sample at all: it goes into one <style> appended last in the frame's head, whose
  selector is the element's own tag and never :root — and that rule is printed at the
  bottom of the panel to be copied, which is worth more than the knobs are.

  An untouched knob writes nothing at all. Defaults are placeholders, not values, so
  emptying a control is how you reset it.

  No manifest, no tabs — a page that does not use one renders byte-identically to before,
  and a page that never loads the bundle pays nothing for the attribute existing.

Changed

• The DOM of the bar above the preview. viewport-widths used to put role="group" on
  .code-preview-bar itself; the buttons now sit in a .code-preview-widths group inside it,
  and the bar is a plain strip that the options panel's tab list shares. One bar means one
  border, one set of top corners and one height to reserve however many things end up in it.
  Only affects CSS or scripts that targeted .code-preview-bar[role="group"] directly.
• code-preview:not(:defined)[viewport-widths]::before is now
  code-preview:not(:defined):is([viewport-widths], [manifest])::before, since manifest
  puts a bar there too. --code-preview-options-height (default 12rem) joins
  --code-preview-height and --code-preview-bar-height, and matters only with
  tab="options" — the one case where upgrading hides something, so the code block is hidden
  from the start and the panel's space held instead.

Full Changelog: v0.1.0...v0.2.0