* feat(server): add --dangerous-bypass-auth and --keep-alive flags
- --dangerous-bypass-auth disables bearer-token auth on every REST and
WebSocket route and advertises it via /api/v1/meta so the web UI skips
the token prompt; the startup banner drops the token and shows a red
danger notice
- --keep-alive keeps the daemon running instead of idle-killing after 60s;
implied by --host / --allowed-host and always on in --foreground mode
* fix(server): address review feedback on bypass-auth
- keep the token and skip the bypass notice when a daemon is reused, since
the requested --dangerous-bypass-auth flag is not applied to the
already-running server
- clear the cached dangerous_bypass_auth web state on HTTP 401 so a stale
bypass value cannot hide the token prompt after the server restarts
without the flag