getOrders fails on HTTP wire decimal fields and loses broker string order IDs

[yodaliu]

getOrders summaries assumed OpenOrder decimal fields were in-process Decimal instances, so HTTP wire responses with string fields could fail with:

order.totalQuantity.equals is not a function

This issue was observed on Alpaca. Not sure if this is a cross-broker wire-format issue. Alpaca also exposes a related order ID problem because Alpaca order IDs are UUID strings, while Order.orderId is numeric and may be 0, so summaries can lose the real broker-native order ID.

Reference:

• https://docs.alpaca.markets/us/reference/getallorders-1

Expected behavior:

• getOrders should handle both Decimal instances and HTTP wire string values.
• UNSET_DECIMAL sentinel values should still be omitted from summaries.
• Broker-native string order IDs should be preserved when available.