v2.0.6

fix: add borders to auth block table cells for every auth type

The auth block rendered without any cell borders, unlike the other
request tables (Headers, Query Params, etc.), making rows/columns hard
to tell apart:

- Wrap the whole block in the same bordered/rounded card used by
  Table.tsx.
- Give OAuth2's custom key-value rows a row divider (they're plain flex
  divs, not real <td> elements, so they never picked up the table cell
  border rule).
- Force a full-opacity, all-sides border on the real <table> cells used
  by Basic/Bearer/API Key and OAuth2's grant-fields table via a plain
  <style> tag instead of a Tailwind class — the host app's Tailwind
  build only scans apps/ui/src, never plugin source, so an
  arbitrary-variant class that isn't already used verbatim there is
  silently never compiled.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>