fix: change Transaction.value type from number to string to prevent overflow (#1836)

JavaScript's Number type can only safely represent integers up to 2^53-1.
When the API returns large wei values (like NFT prices in wei), they can
overflow and become negative values like -1617240366657743600.

This fix changes Transaction.value type from number to string, which:
- Prevents integer overflow for large wei values
- Works with ethers.js which accepts strings as BigNumberish
- Matches how the API should serialize large integer values

Author: ryanio

src/orders/types.ts

@@ -79,7 +79,7 @@ type Transaction = {
   function: string;
   chain: number;
   to: string;
-  value: number;
+  value: string;
   input_data:
     | {
         // For fulfillAdvancedOrder