fix: complete beta accessibility and UX review

[RentnerKev]

Summary

Perform the final broad UX/accessibility review before the first Beta.

Alpha 3 already completed the major visual cleanup.

This issue is NOT another redesign.

Review

• keyboard navigation
• visible focus
• dialogs
• selects
• calendars
• action menus
• tables
• filters
• loading states
• empty states
• error states
• mobile/responsive behavior
• accessible names
• labels
• contrast
• screen-reader-relevant semantics where practical

Core Journeys

• setup
• login
• users/roles
• Proxy Hosts
• Redirect Hosts
• certificates
• Trusted CAs
• Access Policies
• Access Logs
• Audit Logs
• settings/account

Acceptance Criteria

• no known P0/P1 accessibility issue
• core flows keyboard-usable
• no major responsive regression
• no major inconsistent UI state
• tests added where practical

Priority

P1

Dependencies and sequencing

Builds on completed Alpha 3 UI work #52, #53, #54, #55, #56, #57 and #58; this is validation/remediation, not another redesign. Review final new journeys from #64, #65 and #66 and relevant tester feedback #73. Final results gate #75.

Alpha 4 prerequisite

Review the completed Alpha 4 log pagination (#80), durable host/certificate flow (#81), loading/error states (#83), and management-origin setup changes (#84), alongside the final Beta journeys. Alpha 4 targeted fixes do not replace this broad review.