feat(ui): breadcrumb (Space › parent › page) + export menu (md/txt/html/pdf) on pages & spaces

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/views/space.js

@@ -2,6 +2,7 @@
 // pages & references table below (all pages; refs up to the API max).
 import { api } from '../api.js';
 import { el, mount } from '../dom.js';
+import { exportMenu } from '../components/export_menu.js';
 
 function projItem(p) {
   return el('li', {},
@@ -51,7 +52,17 @@ export async function render(main, ctx) {
   ];
 
   mount(main,
-    el('h1', { class: 'view-h1' }, space.name),
+    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.')),
 
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