Module split 

Functions

split_bill_paisa

Splits total_paisa across count people so the parts sum EXACTLY to total. Port of lib/core/bill_splitter.dart splitBillPaisa. div_euclid/rem_euclid match Dart ~//% on non-negative totals; on negatives Rust keeps the exact sum where Dart drifts (improvement, real inputs are non-negative). Counts past 10k return empty (FFI OOM guard).