Add public API status/health indicator to SettingsScreen.tsx

[christabel888]

Context: src/components/SettingsScreen.tsx (with src/hooks/useSettingsScreen.ts) already exists as the natural home for a status indicator.

Where:

• src/components/SettingsScreen.tsx

What to do:

• Add a public API status/health indicator, useful once the app depends on more backend endpoints than before.

Suggested approach:

1. Add a simple status indicator to SettingsScreen.tsx -- a basic "API: OK / Degraded" check is enough, this doesn't need a full status-page integration.

Watch out for:

• None -- this is intentionally small and well-scoped.

Definition of done:

• Settings screen shows current API status