Add social preview image and iPhone/Android EXIF guides

New 1200x630 preview card with the new logo, two high-intent guides,
cross-linked related lists, updated sitemap, footer and guides index.

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

public/sitemap.xml

@@ -15,6 +15,16 @@
     <lastmod>2026-10-20</lastmod>
     <priority>0.7</priority>
   </url>
+  <url>
+    <loc>https://untrace.realbrain.cc/guides/remove-exif-data-iphone/</loc>
+    <lastmod>2026-10-20</lastmod>
+    <priority>0.7</priority>
+  </url>
+  <url>
+    <loc>https://untrace.realbrain.cc/guides/remove-exif-data-android/</loc>
+    <lastmod>2026-10-20</lastmod>
+    <priority>0.7</priority>
+  </url>
   <url>
     <loc>https://untrace.realbrain.cc/guides/what-is-exif-data/</loc>
     <lastmod>2026-10-20</lastmod>