Add a Qikbar command bar (⌘K) to this app.

Qikbar is an open-source, zero-dependency command bar library (npm package `@qikbar/qikbar`). The full documentation for AI agents is at https://qikbar.com/llms-full.txt. Read it before you start.

Do the following:

1. Install it with this project's package manager (`npm install @qikbar/qikbar`, `pnpm add @qikbar/qikbar`, `yarn add @qikbar/qikbar` or `bun add @qikbar/qikbar`).

2. Find how this app does routing (Next.js, React Router, TanStack Router, Vue Router, SvelteKit, Remix, Astro, or plain links). Mount Qikbar once, near the root:
   - React and Next.js: render `<Qikbar … />` from `@qikbar/qikbar/react` in the root layout or a top-level client component.
   - Anything else: call `createQikbar({ … })` from `@qikbar/qikbar` once on the client.
   - Pass the router's navigate function as `navigate`, for example `navigate: (href) => router.push(href)`.

3. Add a `routes` entry for every main page you find (path, title, an `icon` from the built-in icon names, and `keywords`). Group them with `section`.

4. Add `commands` for the main actions a user takes (create, invite, toggle, sign out, open settings…). Wire them to the app's existing functions. Use `view: form({...})` for actions that need input. Use `arguments` for one or two quick text inputs.

5. For each main kind of record (projects, users, documents, orders…), add a `sources` entry. It calls the app's existing API or data layer with the query and returns items (`title`, `subtitle`, `href`, `icon`). Respect the `signal` for cancellation.

6. Make it match the app's design. Set `theme: { vars: { … } }` from the app's colors, font, and radius (accent, bg, fg, border, radius, font). Set `appearance: 'auto'` if the app has a dark mode.

7. Add a visible trigger, for example a "Search… ⌘K" button in the header, with the `data-qikbar-open` attribute or `useQikbar().open()`.

8. If the app already uses an AI provider, or the user wants AI: add a server route with `createHandler` from `@qikbar/qikbar/server`, and set `ai: proxy('/api/qikbar')` on the client. Keep API keys on the server. Otherwise skip AI.

9. Add the built-in extensions that fit: `calculator()`, `themeSwitcher()` (only if the app has dark mode), and `shortcuts()` from `@qikbar/qikbar/extensions`.

10. Run the type checker and the build. Fix any errors. Then summarize what you added, with file paths.

Keep the changes small and idiomatic for this codebase. Don't add new dependencies besides `@qikbar/qikbar`.