Property listings site for an agent

Build a listings site for a small real estate agency.

Core features:
1. Public listing gallery with filters (price, beds, area)
2. Detail page: photos, map, features, agent contact
3. Lead form on each listing, notify the assigned agent
4. Admin: add/edit listings, mark sold, feature on homepage

Data: listings, photos, agents, leads.
Must-haves: SEO per listing (title/OG), image lazy load, sitemap.