- make PaymentFeeBudget proportional fee and flat cutoff fee configurable - closes https://github.com/spesmilo/electrum/issues/7622 - increase flat cutoff fee default to 10 sat - closes https://github.com/spesmilo/electrum/issues/7669 - rm RouteEdge.is_sane_to_use() (per edge limit) and just rely on budgets (per route limit)