routes.go: HTTP route registration with OAuth middleware
- Converted all handlers from (c *Crawler) to (d *Dashboard)
- Removed url.1440.news short URL handling (belongs in shortener service)
- Removed /internal/crawl endpoint (requires crawler)
main.go: Entry point for standalone dashboard service
- Uses NewDashboard with connection string from DATABASE_URL
- Starts stats update loop and HTTP server
