feat(mindspace): add achievements showcase with paginated management

Ship the M成果 page with list/delete UX, fix deletePage for incomplete page records, route /space/achievements, and add M成果 under the WeChat M空间 menu.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/types.ts

@@ -870,6 +870,12 @@ export type MindSpacePage = {
   status: 'draft' | 'reviewing' | 'risk_found' | 'ready' | 'published' | 'protected' | 'expired' | 'offline';
   visibility: 'private' | 'internal' | 'public';
   publicationAccessMode?: 'public' | 'password' | 'private_link' | 'time_limited' | 'login_required' | 'owner_only' | null;
+  publicationId?: string | null;
+  publicationStatus?: string | null;
+  viewCount?: number;
+  clickCount?: number | null;
+  statsSource?: 'none' | 'publication' | 'umami';
+  publishedAt?: number | null;
   publicationUrl?: string | null;
   workspaceRelativePath?: string | null;
   workspacePublicUrl?: string | null;