Consolidate Q&A share buttons — X and Facebook now share image; v1.0.13

Replaced the separate text-link X/FB buttons and the duplicate image buttons
with a single X and Facebook button each that share the generated quote card.
Keeps button row to 5: Upvote, X Share, Facebook Share, Copy link, Save image.

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "1.0.12",
+  "version": "1.0.13",
   "type": "module",
   "scripts": {
     "dev": "vite",