fix(seo): Wave 1 — fix critical SEO gaps

- Fix duplicate faq/ruFaq keys in dice.json, list.json, colors.json
- Add <main> landmarks to about/privacy pages (EN + RU)
- Move YandexRTB after <main> on homepage
- Add x-default hreflang to BaseLayout
- Configure sitemap i18n with hreflang alternates
- Add Open Graph + Twitter Card meta tags
- Create default OG image (1200x630)

.sisyphus/run-continuation/ses_1dca376a3ffewdLYKY0T5iMPdZ.json

@@ -0,0 +1,10 @@
+{
+  "sessionID": "ses_1dca376a3ffewdLYKY0T5iMPdZ",
+  "updatedAt": "2026-05-13T22:04:09.510Z",
+  "sources": {
+    "background-task": {
+      "state": "idle",
+      "updatedAt": "2026-05-13T22:04:09.510Z"
+    }
+  }
+}

.sisyphus/run-continuation/ses_1de6ede59ffexUwt5C0sddEWwR.json

@@ -1,10 +1,10 @@
 {
   "sessionID": "ses_1de6ede59ffexUwt5C0sddEWwR",
-  "updatedAt": "2026-05-13T13:53:55.077Z",
+  "updatedAt": "2026-05-13T22:03:12.991Z",
   "sources": {
     "background-task": {
       "state": "idle",
-      "updatedAt": "2026-05-13T13:53:55.077Z"
+      "updatedAt": "2026-05-13T22:03:12.991Z"
     }
   }
 }