Admin: split long pages into tabs instead of scrolling; v2.9.2

- Shared tab bar; chosen tab is remembered per page
- Current Series: Main Series / Second Series / Launch: Main / Launch: Second
- Resources, Footer & Global, SEO, Legal, Start Here, Custom Links: former "Jump to" scroll links are now tabs
- Dashboard: Overview / Recent Activity / Study Users
- Studies editor: Lessons / Study Settings

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.9.1",
+  "version": "2.9.2",
   "type": "module",
   "scripts": {
     "dev": "vite",