Retrieve a paginated list of loans that are currently marked refinance-eligible (i.e. the stored isRefinanceEligible flag is true). The response shape, authentication, filtering, sorting, and pagination are identical to GET /api/loans — this endpoint simply pre-applies the refinance-eligibility filter on the server. Refer to GET /api/loans for the full list of supported query parameters, filter operators, and sort syntax. When no loans are currently eligible, returns 200 OK with an empty data array. Eligibility is re-evaluated by a nightly job; for real-time per-loan availability use GET /api/loans/{loanUuid}.