Bluesky social icon is invisible for partner cards on Partners page

[h30s]

Problem

On the Partners page (/partnership/partners/), partner organizations (such as pyOpenSci) have a Bluesky profile configured in pages/partnership/partners/index.md:

- name: pyOpenSci
  bluesky: https://bsky.app/profile/pyopensci.bsky.social
  url: https://www.pyopensci.org

The template in theme/partners.html (line 56) attempts to render the Bluesky icon via <use xlink:href="#bluesky"/>:

{% if 'bluesky' in partner %}<a href="{{ partner.bluesky }}" class="icon-btn" target="_blank" rel="noopener" aria-label="Bluesky"><svg class="icon"><use xlink:href="#bluesky"/></svg></a>{% endif %}

However, in theme/icons/sprites.svg (lines 20–25), <symbol id="bluesky"> is commented out:

<!-- bluesky -->
<!--
<symbol id="bluesky" viewBox="0 0 24 24">
  <path d="M12 11.5c2.4-3.4 4.9-5.5 7.3-5.5 1.7 0 2.7 1.3 2.7 2.8 0 3.3-3.6 4.6-6.7 3.7 .2 2.6 1.6 4.8 4.2 6-3.5 .2-6-1.4-7.5-3.4-1.5 2-4 3.6-7.5 3.4 2.6-1.2 4-3.4 4.2-6-3.1 .9-6.7-.4-6.7-3.7 0-1.5 1-2.8 2.7-2.8 2.4 0 4.9 2.1 7.3 5.5z" fill="currentColor"/>
</symbol>
-->

And theme/base.html does not include #bluesky either. Because the symbol is missing from the DOM, the icon renders completely blank/empty.

User Impact

Visitors browsing partner organizations see an empty, invisible box in place of the Bluesky icon button on partner cards. Users cannot identify which social platform the link is for without inspecting the DOM.

Expected Behavior

The #bluesky SVG symbol should be active in theme/icons/sprites.svg (or defined in theme/base.html) so that partner cards display the Bluesky icon clearly.

Relevant Code References

• theme/icons/sprites.svg (lines 20–25)
• theme/partners.html (line 56)
• pages/partnership/partners/index.md (line 67)