Props tab live-edits template preview; tree-shaking shipped

Minor Changes

• 9605c04: Add a Props tab to the preview toolbar for live-editing the props a template is rendered with. Edits re-render the preview without changing the template's PreviewProps, invalid JSON is flagged inline, and a reset restores the template defaults.

Patch Changes

• d7743bc: Ship per-module build output with sideEffects: false so bundlers can tree-shake unused components. Importing a component no longer pulls prismjs, marked, and tailwindcss into the bundle unless CodeBlock, Markdown, or Tailwind is actually used.
• 7b32bf6: Fixed toolbar tabs not responding on statically built previews when the page was opened with a toolbar-panel query param in the URL.