feat(map-server): add screenshot to updateModelContext and remove reverse geocode + rounded corners (#340)

* feat(map-server): add screenshot to updateModelContext and remove rounded corners

- Remove border-radius and overflow: hidden from cesiumContainer CSS
- Capture map canvas as base64 PNG and include in updateModelContext
- Only include image if host supports image content blocks

* feat(map-server): reduce screenshot size for fewer tokens

- Scale down to max 256px (longest dimension)
- Use PNG for better quality with map graphics

* prettier

examples/map-server/mcp-app.html

@@ -19,8 +19,6 @@
         #cesiumContainer {
             width: 100%;
             height: 100%;
-            border-radius: .75rem;
-            overflow: hidden;
         }
         #fullscreen-btn {
             position: absolute;