Phone/LAN testing previously required editing both app.ts (cors origin) and
auth.ts (better-auth trustedOrigins). Now both read env.WEB_ORIGINS, parsed from
a comma-separated CORS_ORIGINS env var (default http://localhost:5173). To test
from a phone, set CORS_ORIGINS to include the LAN origin and restart the API — no
code edit. Documented in .env.example. Also fixed the worker README (db:migrate
creates ./data/app.db, not ./.tmp; phone step now uses CORS_ORIGINS). API tests
36/36 green; typecheck clean.
