refactor(ui): establish reusable components

[Mathious6]

What changed

• establish reusable Button, Dialog, Menu, and Pill primitives
• refresh the compact interface with an OpenCode-inspired visual language
• clarify selected-scope Probe and Export actions without a count or Clear control
• improve keyboard row selection, context menus, and focus behavior

Stack

Depends on the release-notes PR. Review this PR by commit or with its base branch.

Verification

• bun run check
• bun run build