feat(migrate): BookStack importer

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

migrate/sources/bookstack.js

@@ -0,0 +1,26 @@
+import * as pages from '../../lib/db/repos/pages.js';
+import * as map from '../../lib/db/repos/migration_map.js';
+
+const SYS = { kind: 'system', id: null };
+const slugify = (s) => (s || '').toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/(^-|-$)/g, '').slice(0, 60) || 'page';
+
+// BookStack REST: list GET /api/pages → {data:[{id,name}]}; detail GET /api/pages/:id
+// → {id,name,markdown,html}. Auth header: "Token <id>:<secret>".
+export async function importBookstack({ apiUrl = process.env.BOOKSTACK_URL, tokenId = process.env.BOOKSTACK_TOKEN_ID, tokenSecret = process.env.BOOKSTACK_TOKEN_SECRET, spaceId, dryRun = false, fetchImpl = fetch }) {
+  const headers = { Authorization: `Token ${tokenId}:${tokenSecret}` };
+  const listRes = await fetchImpl(`${apiUrl}/api/pages`, { headers });
+  if (!listRes.ok) throw new Error(`bookstack list ${listRes.status}`);
+  const { data = [] } = await listRes.json();
+  let created = 0;
+  for (const item of data) {
+    if (await map.seen('bookstack', `page:${item.id}`, 'page')) continue;
+    created++; if (dryRun) continue;
+    const dRes = await fetchImpl(`${apiUrl}/api/pages/${item.id}`, { headers });
+    if (!dRes.ok) throw new Error(`bookstack page ${item.id} ${dRes.status}`);
+    const d = await dRes.json();
+    const body = d.markdown && d.markdown.trim() ? d.markdown : (d.html || '');
+    const p = await pages.create({ space_id: spaceId, slug: slugify(d.name), title: d.name || 'Untitled', body_md: body }, SYS);
+    await map.record('bookstack', `page:${item.id}`, 'page', p.id);
+  }
+  return { created };
+}