Add synor-hosting crate for decentralized web hosting with:
- Name Registry: On-chain name→CID mapping with ownership, expiry,
and custom domain linking
- Domain Verification: CNAME/TXT DNS verification for custom domains
- Hosting Router: Host-based routing with SPA support, redirects,
and custom headers
- synor.json: Project configuration for build, routes, and error pages
Users can deploy to myapp.synor.cc and optionally link custom domains.
23 tests passing.