admin command palette with public-id resolution + keyboard-driven backoffice

[jaspermayone]

Why

Quality-of-life multiplier for admin work once user volume grows: paste any public ID or search a name and jump straight to the record.

What

• Typeahead endpoint that resolves Stripe-style public-ID prefixes (usr_, PWL…, service/webhook prefixes) via a whitelist→model map, falling back to scoped search (policy_scope'd, adopt pundit with fail-closed policies #88).
• Keyboard-driven nav in the admin UI (j/k/enter list navigation, set_keyboard_shortcut(:back, path)), with a declarative per-controller hints registry and per-admin "seen hints" tracking.

Reference

• https://github.com/hackclub/auth/blob/main/app/controllers/backend/kbar_controller.rb
• https://github.com/hackclub/auth/blob/main/app/lib/backend/hints.rb