fix(ucs): mirror connector minor_amount_captured on UCS capture path (PayPal)

Shadow validation flags a router-data type diff on PayPal capture: `router.typeDiff:minor_amount_captured` — native HS leaves `minor_amount_captured = null` (PayPal sets only `amount_captured`), but the UCS-shadow capture gateway re-derives it from gRPC `captured_amount`, producing a number.

Fix: carry `minor_amount_captured` explicitly in `PaymentServiceCaptureResponse` (UCS) and map it in the HS capture gateway instead of re-deriving from `captured_amount`.

Tracks juspay/hyperswitch-cloud#16996. UCS side: juspay/connector-service#1606.

Start by tracing PaymentServiceCaptureResponse through the UCS capture path into the HS capture gateway, then compare the PayPal native and UCS-shadow capture responses. Ensure the explicit minor_amount_captured value is carried and mapped consistently, and verify that shadow validation no longer reports router.typeDiff:minor_amount_captured.

Written by the indexing model from the issue text.