Description

Replace News page (headlines/briefs/feeds/hackernews) with a 2x2 grid of the four screamer brief categories, one per quadrant. Panel titles = category names. Removed dead render_feeds/render_briefs; feeds still feeds the paper.

Acceptance Criteria

• #1 News page shows 4 brief-category quadrants, titled by category
• #2 No headlines/feeds/hackernews on News page