The gateway connection resolver short-circuited to "请先登录 svc.plus"
whenever the account was signed out, before checking whether a manual
bridge was configured or whether capability discovery was still running.
A saved manual bridge could therefore never be used while signed out.
- Only emit the signed-out prompt when neither an account session nor a
manual bridge is configured (`!accountSignedIn && !bridgeConfigured`).
- Gate the sync-blocked branch on `accountSignedIn` so it no longer
hijacks the manual-bridge discovery path.
Adds tests covering manual-bridge discovery and discovery-failure while
signed out. See docs/cases/manual-bridge-login-state/README.md.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
