Extend TypeScript client and add Leaflet asset demo.

This adds typed asset APIs to the geo client, covers the 3D/image upload-share flow in integration tests, and introduces a simple Leaflet web demo that places objects on map features and manages sharing visibility via backend links.

Made-with: Cursor

docs/assets-storage-and-sharing.md

@@ -38,12 +38,42 @@ Each `properties.assets` item includes:
 5. Change visibility:
    - `PATCH /v1/assets/{id}` with `{"isPublic": false|true}`
 
+## Example asset payload inside a feature
+
+```json
+{
+  "id": "feature-id",
+  "type": "Feature",
+  "properties": {
+    "name": "Palm Tree Spot",
+    "assets": [
+      {
+        "id": "asset-id",
+        "kind": "3d",
+        "name": "Palm Tree",
+        "description": "Low-poly tree",
+        "checksum": "abc123...",
+        "ext": "glb",
+        "isPublic": true,
+        "link": "/v1/assets/asset-id/download"
+      }
+    ]
+  }
+}
+```
+
 ## Visibility rules
 
 - Owner can always download their own asset.
 - Other authenticated users can download only when `isPublic=true`.
 - Owner can toggle `isPublic` at any time.
 
+## Deduplication behavior
+
+- Deduplication is per owner and file identity (`owner_key + checksum + ext`).
+- If the same user submits the same checksum/extension again, backend reuses existing asset metadata.
+- One asset can be linked to multiple features without duplicating object storage files.
+
 ## Spatial readiness for 3D search
 
 Feature storage is prepared for future spatial search: