Summary

Redesign the commons interpretation dashboard UI — layout, styling, and copy — without changing connect/disconnect/test behavior. This is PR 5 of 5 in the milestone-1 stack.

Background

PR #46 will make email/password login work, but the UI will still be a basic form. This issue will bring the dashboard in line with the intended commons design and will leave room for additional interpreter providers later via a dropdown scaffold.

Scope

• Add dashboard.css — hero header, status grid, account card, badges, panels, responsive layout
• Restructure dashboard.html:
  • Disconnected: welcome hero, interpreter provider dropdown (None / SUSI), sign-in section
  • Connected: personalized welcome, status grid (interpreter, event, slug, live interpretation on/off), connected-account card with View rooms / Test / Sign out, settings panel for enable toggle
• Update susi_login_form.html and susi_connected_panel.html to match the new layout
• Add view context: susi_welcome_name, interpretation_providers, selected_provider (auto-select SUSI after a failed connect attempt)
• Add small JS to show/hide provider panels when the dropdown changes
• Update tests for renamed labels/copy

Acceptance criteria

• pytest and ruff check . pass
• When not connected: welcome hero, provider dropdown, and SUSI sign-in panel will be visible when SUSI is selected
• Connect flow will still work; page will switch to the connected layout
• When connected: status grid, account card, server host, and enable toggle + Save will display correctly
• Test connection, Sign out, and View rooms links will work
• A failed login will keep SUSI selected as the provider and will show errors
• Layout will hold up on narrow viewports (no broken panels)