Update documentation across README, installation, and quick-start guides
to highlight the new relay-based access method with WireGuard + TLS
end-to-end encryption. Changes include:
- Recommend `hapi server --relay` as the default startup command
- Explain URL and QR code generation in terminal for instant access
- Note end-to-end encryption for security assurance
- Reorganize self-hosted tunnel options (Cloudflare, Tailscale, IP)
- Update website installation steps and add E2EE badge
Introduce comprehensive documentation of HAPI's Seamless Handoff feature:
- README: Add Seamless Handoff to Features section
- how-it-works: Add complete Seamless Handoff guide with local/remote modes and switching workflow
- quick-start: Add Seamless Handoff link to Next steps
- AppShowcase: Add third card featuring "Switch Freely" mode switching capability
- Locales: Update English and Chinese translations for showcase content
- Support both local and remote server deployment
- Add direct public IP access option for remote servers
- Remove tunnel requirement messaging
- Organize remote access options with details sections
- Set VitePress base to '/docs/' for serving documentation at /docs/ route
- Update favicon path in head config to '/docs/favicon.ico'
- Add build:site script to build website and docs, then merge outputs
weishu