feat(event): show supplementary links in detail sidebar

Surfaces the new event link fields from sanity PR #242 (registration,
code of conduct, accessibility info, schedule, call for speakers) inside
the event detail sidebar card, below the existing 'Event website' button.

Accessibility info renders link + summary together when both are
present, associated via aria-describedby so the summary is announced as
the link's description. When only a summary exists, it renders as plain
text in the list.

Also fixes a pre-existing gap on the 'Event website' button: external
link indication was visual only. Added sr-only '(opens external site)'
text to match the pattern used in StaticEvent.astro.

Author: mattobee

src/pages/events/[slug].astro

@@ -109,6 +109,31 @@ const enumeratedChildTypes = (() => {
   return `${joined} at ${event.title}`;
 })();
 
+// Supplementary sidebar links
+const supplementaryLinks = [
+  event.registration && { href: event.registration, label: 'Registration' },
+  event.codeOfConduct && {
+    href: event.codeOfConduct,
+    label: 'Code of conduct',
+  },
+  event.accessibilityInfo?.url && {
+    href: event.accessibilityInfo.url,
+    label: 'Accessibility information',
+    summary: event.accessibilityInfo.summary,
+  },
+  event.schedule && { href: event.schedule, label: 'Schedule' },
+  event.callForSpeakersLink && {
+    href: event.callForSpeakersLink,
+    label: 'Call for speakers',
+  },
+].filter(Boolean) as Array<{ href: string; label: string; summary?: string }>;
+
+const hasAccessibilitySummaryOnly =
+  event.accessibilityInfo?.summary && !event.accessibilityInfo?.url;
+
+const hasSidebarLinks =
+  supplementaryLinks.length > 0 || hasAccessibilitySummaryOnly;
+
 // JSON-LD structured data
 const jsonLd = {
   '@context': 'https://schema.org',
@@ -302,7 +327,7 @@ const jsonLd = {
 
       <div class="event-detail-body">
         {
-          (event.website || event.organizer) && (
+          (event.website || event.organizer || hasSidebarLinks) && (
             <aside class="event-detail-sidebar">
               <wa-card class="event-detail-sidebar__card" appearance="outlined">
                 <p>
@@ -371,9 +396,64 @@ const jsonLd = {
                     style="width: 100%;"
                   >
                     Event website
+                    <span class="sr-only"> (opens external site)</span>
                     <wa-icon slot="end" name="arrow-up-right-from-square" />
                   </wa-button>
                 )}
+                {hasSidebarLinks && (
+                  <>
+                    <h2 class="sr-only">Event resources</h2>
+                    <ul role="list" class="event-detail-sidebar__links">
+                      {supplementaryLinks.map((link) =>
+                        link.label === 'Accessibility information' &&
+                        link.summary ? (
+                          <li>
+                            <a
+                              href={link.href}
+                              rel="noopener noreferrer"
+                              target="_blank"
+                              aria-describedby="a11y-info-summary"
+                            >
+                              {link.label}
+                              <wa-icon
+                                name="arrow-up-right-from-square"
+                                label="(opens external site)"
+                              />
+                            </a>
+                            <p
+                              id="a11y-info-summary"
+                              class="text-small text-muted"
+                            >
+                              {link.summary}
+                            </p>
+                          </li>
+                        ) : (
+                          <li>
+                            <a
+                              href={link.href}
+                              rel="noopener noreferrer"
+                              target="_blank"
+                            >
+                              {link.label}
+                              <wa-icon
+                                name="arrow-up-right-from-square"
+                                label="(opens external site)"
+                              />
+                            </a>
+                          </li>
+                        )
+                      )}
+                      {hasAccessibilitySummaryOnly &&
+                        !event.accessibilityInfo?.url && (
+                          <li>
+                            <p class="text-small text-muted">
+                              Accessibility: {event.accessibilityInfo!.summary}
+                            </p>
+                          </li>
+                        )}
+                    </ul>
+                  </>
+                )}
               </wa-card>
             </aside>
           )
@@ -583,6 +663,27 @@ const jsonLd = {
     margin-top: var(--p-space-xs);
   }
 
+  .event-detail-sidebar__links {
+    list-style: none;
+    padding: 0;
+    margin-top: var(--p-space-xs);
+    padding-top: var(--p-space-xs);
+    border-top: 1px solid var(--s-color-border);
+    display: flex;
+    flex-direction: column;
+    gap: var(--p-space-2xs);
+  }
+
+  .event-detail-sidebar__links a {
+    display: inline-flex;
+    align-items: center;
+    gap: var(--p-space-3xs);
+  }
+
+  .event-detail-sidebar__links p {
+    margin: var(--p-space-3xs) 0 0;
+  }
+
   @media (min-width: 769px) {
     .event-detail {
       max-width: none;

src/types/event.ts

@@ -52,6 +52,11 @@ export interface Event {
   location?: string;
   isFree?: boolean;
   website?: string;
+  registration?: string;
+  codeOfConduct?: string;
+  accessibilityInfo?: { url?: string; summary?: string };
+  schedule?: string;
+  callForSpeakersLink?: string;
   parent?: { _ref: string };
   parentEvent?: { title: string; slug?: { current: string } };
   children?: ChildEvent[];