feat(app-admin): command palette (DI-based command registration)

[adrians5j]

Summary

Adds a ⌘K / Ctrl+K command palette to the Webiny admin app: fuzzy search over navigation destinations and registered actions, keyboard-driven, design-system styled.

Builds on the ideas from #5065 (thanks @Pavel910) — adopting its DI-based command registration and MobX presenter, combined with a design-system UI, navigation derived from the sidebar menus, an in-palette detail view, and working global shortcuts.

What's included

• DI command registration (@webiny/app-admin): a Command abstraction, a MobX CommandPalettePresenter resolving commands via container.resolveAll(Command), and a CommandPaletteFeature (registered in Admin.tsx, exported from the barrel).
• Design-system UI (@webiny/app-admin-ui): scrim + panel, grouped list, header "Search or jump to… ⌘K" trigger, breadcrumb sections, ancestor icon inheritance, footer hints — all on DS tokens. Driven by the presenter (observer).
• Navigation group auto-derived from the registered admin menus (leaf Menu.Links → navigate on select), merged with DI command groups.
• detailView: a command can render a React form inside the palette; submit runs execute(data). Back returns to the list, Esc closes.
• Global shortcuts: a command's shortcut registers a working hotkey (useHotkeys gained a [keys] dep for dynamic re-registration).
• Baseline commands: Copy current URL, Sign out. Plus a demo Send message detail-view command (cmd+shift+m) — flagged, safe to remove.

Registering a command

class MyCommand implements Command.Interface {
  name = "myapp.deploy"; label = "Deploy"; category = "Actions";
  shortcut = "cmd+shift+d";          // optional global hotkey
  execute() { /* ... */ }
  // detailView?: React component rendered inside the palette
}
export const MyCommandImpl = Command.createImplementation({
  implementation: MyCommand, dependencies: [/* DI tokens */]
});
// register inside a feature: container.register(MyCommandImpl)

Notes / follow-ups

• Ships a demo Send message command (remove the container.register(SendMessageCommand) line to drop it).
• Deferred: Recent group (route history / ACO), per-module create actions (new entry, publish, upload, invite), automated tests.
• Known caveat: mod+k shares the useHotkeys zIndex layering — a higher-zIndex layer opened elsewhere can shadow it.

🤖 Generated with Claude Code