Task: Add x-default hreflang to BaseLayout
Date: 2026-05-14

Verification:
- npm run build: PASS (62 pages built)
- grep dist/index.html for x-default: FOUND
  <link rel="alternate" hreflang="x-default" href="https://randify.pro/">
- grep dist/generators/dice/index.html for x-default: FOUND
- grep all dist/*.html for x-default: 62 matches across 62 files

All pages now include x-default hreflang fallback pointing to the English version.
