Add feature geometry PATCH API support and update MapLibre demo to use OSM raster tiles, load all public/owned features, and let logged-in users drag their own feature markers to persist new positions.
Made-with: Cursor
This introduces a MapLibre GL + Three.js web demo for object placement and sharing, and changes asset upload flow to use backend upload endpoints so clients no longer receive direct MinIO URLs.
Made-with: Cursor
