Fix: bold text overridden by typography plugin on links in prose (#1535)

The `@tailwindcss/typography` plugin sets an explicit `font-weight` on
`.prose a` elements, which overrides the bold weight inherited from a
parent `<strong>`. This means MDX like `**[Free Ticket Voucher
Grant](#link):**` renders as `<strong><a>...</a></strong>` but the link
text appears non-bold.

## Fix

Added to the `.prose` block in `src/styles/global.css`:

```css
/* Preserve bold when a link is wrapped in <strong> (e.g. **[text](#link)**).
   The typography plugin sets an explicit font-weight on <a> tags, which
   overrides the inherited bold from a parent <strong>. */
strong a,
a strong {
  font-weight: bold;
}
```

This restores expected bold rendering for `**[text](#link)**` patterns
across all prose/MDX content on the site.

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: egeakman <75242929+egeakman@users.noreply.github.com>

Author: Copilot

src/styles/global.css

@@ -150,6 +150,14 @@ p.cross::after {
     word-break: break-word;
   }
 
+  /* Preserve bold when a link is wrapped in <strong> (e.g. **[text](#link)**).
+     The typography plugin sets an explicit font-weight on <a> tags, which
+     overrides the inherited bold from a parent <strong>. */
+  strong a,
+  a strong {
+    font-weight: bold;
+  }
+
   h1,
   h2,
   h3,