good first issue: show Screenpipe connection status in Settings tab

[hvardhan878]

Problem

The Settings tab has no feedback about whether Screenpipe is actually running. New users often don't realise Screenpipe isn't running until the app has been silently doing nothing for a while.

What to build

A small status row at the top of the Settings tab:

• 🟢 Screenpipe connected — if screenpipe:health returns ok
• 🔴 Screenpipe not running — with a link to screenpipe's install page and a Retry button that re-calls the health check

The health check is already exposed in the preload (window.ghostwork.screenpipe.health()) so no backend work is needed.

Acceptance criteria

• Status row renders above the OpenRouter key field in Settings
• Re-polls every 30 s (or on Retry click) without a full page reload
• Matches the existing dark UI style (no new dependencies)

Files to look at

• src/renderer/index.html — all UI lives here, search for id="settings"
• src/main/preload.ts line 59 — screenpipe.health() is already wired up