Study pages: progress bar, collapsible chapters, compact upcoming lessons, class-based badges, cleaner sign-in/enroll gates; v2.10.7

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "2.10.6",
+  "version": "2.10.7",
   "type": "module",
   "scripts": {
     "dev": "vite",