feat(changelog): make release sections collapsible

Add toggle buttons for changelog sections with item counts and chevrons
Style expanded states and responsive layout for the new controls

src/pages/changelog.astro

@@ -837,6 +837,63 @@ import BaseLayout from '../layouts/BaseLayout.astro';
   </main>
 </BaseLayout>
 
+<script is:inline>
+  const changelogSections = document.querySelectorAll('.changes-section');
+
+  changelogSections.forEach((section, index) => {
+    const title = section.querySelector('.changes-title');
+    const list = section.querySelector('.changes-list');
+
+    if (!(title instanceof HTMLElement) || !(list instanceof HTMLElement)) {
+      return;
+    }
+
+    const itemCount = list.querySelectorAll(':scope > li').length;
+    const listId = `changes-list-${index + 1}`;
+    const toggle = document.createElement('button');
+    const titleContent = document.createElement('span');
+    const meta = document.createElement('span');
+    const count = document.createElement('span');
+    const chevron = document.createElement('span');
+
+    toggle.type = 'button';
+    toggle.className = 'changes-title changes-toggle';
+    toggle.setAttribute('aria-expanded', 'false');
+    toggle.setAttribute('aria-controls', listId);
+
+    titleContent.className = 'changes-toggle-main';
+    while (title.firstChild) {
+      titleContent.appendChild(title.firstChild);
+    }
+
+    meta.className = 'changes-toggle-meta';
+    count.className = 'changes-count';
+    count.textContent = `(${itemCount})`;
+
+    chevron.className = 'changes-chevron';
+    chevron.setAttribute('aria-hidden', 'true');
+    chevron.textContent = '+';
+
+    meta.append(count, chevron);
+    toggle.append(titleContent, meta);
+
+    list.id = listId;
+    list.hidden = true;
+
+    toggle.addEventListener('click', () => {
+      const isExpanded = toggle.getAttribute('aria-expanded') === 'true';
+      const nextExpanded = !isExpanded;
+
+      toggle.setAttribute('aria-expanded', String(nextExpanded));
+      list.hidden = !nextExpanded;
+      section.classList.toggle('changes-section-open', nextExpanded);
+      chevron.textContent = nextExpanded ? '−' : '+';
+    });
+
+    title.replaceWith(toggle);
+  });
+</script>
+
 <style>
   /* Changelog Page Specific Styles */
   
@@ -1020,6 +1077,11 @@ import BaseLayout from '../layouts/BaseLayout.astro';
     background: var(--color-bg);
     border: 1px solid var(--color-border);
     padding: var(--space-md);
+    transition: border-color 0.2s ease, background-color 0.2s ease;
+  }
+
+  .changes-section-open {
+    border-color: var(--color-accent);
   }
   
   .version-latest .changes-section {
@@ -1128,6 +1190,59 @@ import BaseLayout from '../layouts/BaseLayout.astro';
     font-family: var(--font-mono);
     letter-spacing: 0.05em;
   }
+
+  .changes-toggle {
+    width: 100%;
+    justify-content: space-between;
+    margin-bottom: 0;
+    padding: 0;
+    border: none;
+    background: none;
+    cursor: pointer;
+    text-align: left;
+    color: var(--color-accent);
+  }
+
+  .changes-toggle:hover {
+    color: var(--color-text);
+  }
+
+  .changes-toggle:focus-visible {
+    outline: 2px solid var(--color-accent);
+    outline-offset: 4px;
+  }
+
+  .changes-toggle-main {
+    display: inline-flex;
+    align-items: center;
+    gap: var(--space-xs);
+    min-width: 0;
+  }
+
+  .changes-toggle-meta {
+    display: inline-flex;
+    align-items: center;
+    gap: var(--space-sm);
+    margin-left: var(--space-md);
+    flex-shrink: 0;
+  }
+
+  .changes-count {
+    color: var(--color-text-secondary);
+    font-size: 0.85rem;
+  }
+
+  .changes-chevron {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    width: 1.25rem;
+    height: 1.25rem;
+    border: 1px solid currentColor;
+    border-radius: 999px;
+    font-size: 0.85rem;
+    line-height: 1;
+  }
   
   .changes-icon {
     font-size: 1rem;
@@ -1135,6 +1250,7 @@ import BaseLayout from '../layouts/BaseLayout.astro';
   
   .changes-list {
     list-style: none;
+    margin-top: var(--space-sm);
   }
   
   .changes-list li {
@@ -1212,6 +1328,19 @@ import BaseLayout from '../layouts/BaseLayout.astro';
     .version-number {
       font-size: 1.75rem;
     }
+
+    .changes-toggle {
+      align-items: flex-start;
+      gap: var(--space-sm);
+    }
+
+    .changes-toggle-main {
+      flex: 1;
+    }
+
+    .changes-toggle-meta {
+      margin-left: 0;
+    }
   }
 
   /* Screenshot Showcase */