Add browser and component tests for community feed UI

[ashryanbeats]

Context

We added Vitest coverage around the community feed reader and notifier state logic. Browser/component coverage is useful, but it should come after the feed/notifier architecture settles.

Goal

Add UI-level tests that prove the community feed renders correctly and key user-facing states do not regress.

Scope

• Choose the appropriate Astro-friendly browser/component test setup.
• Test feed rendering on the homepage for available items.
• Test empty/error/fallback states if the UI exposes them.
• Include at least one responsive or browser-level smoke test if practical.

Notes

• This is intentionally deferred. Unit coverage for feed parsing/state should land first.