Add public GET /api/version (current version + GitHub-release update check,
cached, fail-soft) and GET /api/network (detected LAN addresses). Accept
localhost/private-LAN origins in CORS and Better Auth trusted origins via a
shared isAllowedOrigin helper, so staff can reach the app over the clinic
network. The seed-demo.ts fake test data is removed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>