Adds 13 new visual regression baselines:
- Public: about (desktop + mobile), members (desktop + mobile)
- Authenticated desktop: member-account, member-activity, connections,
admin-dashboard, members-detail
- Authenticated mobile: member-dashboard, member-profile,
member-account, connections
Switches to a single serial test.describe with a beforeAll that logs in
once and saves the auth cookie via storageState. This avoids repeated
/api/dev/test-login calls that exhausted the dev server's MongoDB
connections under parallel execution.
Masks added: .tl-time, .stat-val, .item-date, .mc-avatar, .cc-avatar,
.profile-avatar, .filter-count — covering activity timestamps, stat
values, member join dates, avatars, and member counts.
