Addresses failures in login-flows.spec.ts by:
1. Updating the test to correctly interact with the provider-based login modal (clicking the 'nsec' button).
2. Patching the test harness `relayManager` to prevent overwriting test relays with production defaults during login/logout cycles.
3. Hardening `uiCoordinator` to ensure visibility assertions pass reliably by enforcing `style.display` properties.
4. Explicitly initializing test relays in `bitvidTestFixture` to guarantee environment isolation.
Co-authored-by: PR0M3TH3AN <[email protected]>
