refactor(space-view): reuse docHead/descEl in project mode (no double exportMenu)

public/views/space.js

@@ -110,18 +110,8 @@ export async function render(main, ctx) {
   renderProjects();
 
   mount(main,
-    el('div', { class: 'doc-head' },
-      el('h1', { class: 'view-h1', style: { margin: '0' } }, space.name),
-      exportMenu({
-        filenameBase: 'space-' + (space.slug || space.name),
-        getContent: async () => {
-          const full = await Promise.all(pages.map(p => api.get('/api/pages/' + p.id).catch(() => null)));
-          const md = full.filter(Boolean).map(p => `# ${p.title}\n\n${p.body_md || ''}`).join('\n\n---\n\n');
-          return { title: space.name, md };
-        }
-      })
-    ),
-    el('p', { class: 'view-sub' }, space.description || el('span', { class: 'muted' }, 'No description.')),
+    docHead,
+    descEl,
 
     el('div', { class: 'card' },
       el('div', { class: 'card-head' }, projHead,