seo: GA4, breadcrumbs JSON-LD, IndexNow post-deploy, llms.txt

- Add GA4 (G-C9J0D8FFH3) to root layout alongside Yandex.Metrika
- Add BreadcrumbList JSON-LD schema to all inner pages
- Add scripts/indexnow.mjs — submits 30 URLs to IndexNow + Yandex on deploy
- Add indexnow to postdeploy step in package.json
- Update llms.txt with all 8 services and new pages (about/clients/partners)

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

package.json

@@ -6,7 +6,7 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "deploy": "BUILD_DIR=../public_html next build"
+    "deploy": "BUILD_DIR=../public_html next build && node scripts/indexnow.mjs"
   },
   "dependencies": {
     "next": "^15.2.3",