Add Books + editable Recommended Resources sections; improve content block links; v1.1.38

- CustomBlock: add linkUrl/linkLabel fields for a styled button below the body
- Body text auto-linkifies raw URLs into gold anchor tags
- New 'books' placement: Reading List grid on Downloads page (cover, desc, Amazon btn)
- New 'recommended' placement: editable Recommended Resources section on Downloads
  page; falls back to Truth For Life widget when empty
- Admin: Books and Recommended Resources panels added to Content nav

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "1.1.37",
+  "version": "1.1.38",
   "type": "module",
   "scripts": {
     "dev": "vite",