feat: add 2026 network expansion blog post and prose styling

- Add blog post announcing repeater deployments (Lookout Mountain, Morrison Mountain)
- Add coverage map image for Phase 1 deployment
- Add comprehensive prose/typography CSS for blog content formatting
- Update /start page with PeakMesh Etsy store in Where to Buy section
- Reorder store links: Seeed Studio, RAK Wireless, Rokland, Muzi Works, PeakMesh
- Remove locations pages (keeping blog infrastructure only)
- Simplify blog page styling to use custom prose classes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cj-vana