Add task_details to the single-asset endpoint response

GET /assets/{id} never returned task_details (the schema didn't even
declare the field), unlike GET /shots/{id} which already populated it
correctly. This silently broke the asset detail panel's task list -
surfaced while wiring real task data into it on the frontend.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/routers/assets.py

@@ -474,10 +474,19 @@ async def get_asset(
     # This avoids a separate COUNT query
     active_tasks = [task for task in asset.tasks if task.deleted_at is None]
     task_count = len(active_tasks)
-    
+
     asset_data = AssetResponse.model_validate(asset)
     asset_data.task_count = task_count
-    
+    asset_data.task_details = [
+        TaskStatusInfo(
+            task_type=task.task_type,
+            status=task.status,
+            task_id=task.id,
+            assigned_user_id=task.assigned_user_id
+        )
+        for task in active_tasks
+    ]
+
     return asset_data