fix(ara-projects): copy the empty-dependents constant per option (#410)

Every unselected card was handed the same NO_DEPENDENTS object; a caller
mutating one would have moved them all. Spread it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/api/projects/[projectId]/workstreams/queries.ts

@@ -127,7 +127,7 @@ export async function listWorkstreamOptions(
             contractors: selection.contractors,
             workOrders: selection.workOrders,
           }
-        : NO_DEPENDENTS,
+        : { ...NO_DEPENDENTS },
     };
   });
 }