Add codexUI visual command center

[jlonsdalen]

Summary

• add a first visible Visual Command Center on the home screen
• surface system status, active task, PR pipeline, idea queue, and Alfred control in one mobile-first dashboard
• reuse existing codexUI session state instead of inventing backend data

Scope

• no backend expansion
• no new product data sources
• single-file UI change in src/App.vue

Validation

• pnpm exec vue-tsc --noEmit
• pnpm run build:frontend

Notes

• Idea Queue is intentionally honest: if no ideas workspace is connected in the current session, the dashboard shows that instead of fabricating counts.

[friuns2]

This PR feels too broad for one review.

It bundles several distinct changes together: a new home-screen dashboard component, home-page layout changes, title/copy changes, and new status derivation/display logic in App.vue. That makes it harder to review what is a real feature addition versus what is presentation polish versus what is product-copy behavior.

I would strongly prefer this to be split into smaller PRs, for example:

1. Add the VisualCommandCenter component itself.
2. Adjust the home-screen layout/styling.
3. Change home-screen titles/copy/status wording.
4. Any follow-up wiring/refinements.

Smaller PRs would make review faster, reduce regression risk, and make it much easier to discuss each change on its own merits.