port mintlify to fumadocs

lib/navigation.tsx

@@ -0,0 +1,92 @@
+import type * as PageTree from 'fumadocs-core/page-tree';
+import { Icon } from '@/components/icons';
+import { source } from './source';
+import navigation from './navigation.json';
+
+/**
+ * The sidebar is defined in `lib/navigation.json` (same shape as Mintlify's `docs.json`
+ * groups), because the groups do not map 1:1 to folders on disk. Pages that exist in
+ * `content/docs` but are not listed here are still published, just hidden from the sidebar.
+ */
+type NavItem = string | NavGroup;
+interface NavGroup {
+  group: string;
+  icon?: string;
+  pages: NavItem[];
+}
+
+export interface NavLink {
+  label: string;
+  href: string;
+  icon?: string | null;
+}
+
+export const navTabs: NavLink[] = navigation.tabs;
+export const navAnchors: NavLink[] = navigation.anchors;
+
+function pageNode(path: string): PageTree.Item | null {
+  const slugs = path === 'index' ? [] : path.split('/');
+  const page = source.getPage(slugs);
+  if (!page) {
+    console.warn(`[navigation] page not found: ${path}`);
+    return null;
+  }
+
+  return {
+    $id: `page:${path}`,
+    type: 'page',
+    name: page.data.title,
+    url: page.url,
+    icon: page.data.icon ? <Icon name={page.data.icon} /> : undefined,
+  };
+}
+
+function buildItems(items: NavItem[], idPrefix: string): PageTree.Node[] {
+  const out: PageTree.Node[] = [];
+  for (const item of items) {
+    if (typeof item === 'string') {
+      const node = pageNode(item);
+      if (node) out.push(node);
+      continue;
+    }
+
+    const id = `${idPrefix}/${item.group}`;
+    out.push({
+      $id: id,
+      type: 'folder',
+      name: item.group,
+      icon: item.icon ? <Icon name={item.icon} /> : undefined,
+      children: buildItems(item.pages, id),
+    });
+  }
+  return out;
+}
+
+let cached: PageTree.Root | undefined;
+
+export function getNavigationTree(): PageTree.Root {
+  if (cached) return cached;
+
+  const children: PageTree.Node[] = [];
+  for (const group of navigation.groups as NavGroup[]) {
+    // top-level groups render as sidebar section headings
+    children.push({ $id: `sep:${group.group}`, type: 'separator', name: group.group });
+    children.push(...buildItems(group.pages, group.group));
+  }
+
+  cached = { $id: 'root', name: 'Docs', children };
+  return cached;
+}
+
+/** Page paths in sidebar order (first occurrence wins), used for llms-full.txt */
+export function getOrderedPagePaths(): string[] {
+  const seen = new Set<string>();
+  function walk(items: NavItem[]) {
+    for (const item of items) {
+      if (typeof item === 'string') seen.add(item);
+      else walk(item.pages);
+    }
+  }
+  walk(navigation.groups as NavGroup[]);
+  return [...seen];
+}