The Frontier

Core Lightning #9046 fixes KeySend interoperability with LDK by increasing the final CLTV expiry value (safety margin) from 22 to 42. This matches LDK's expectation for receiving KeySend payments.

LDK has promoted zero-fee commitment channels from experimental to production status. This feature replaces two anchor outputs with one shared `pay-to-anchor` output, offering more flexibility for future fee conditions.

LDK #4558 extends receiver-side timeout, previously for multi-path payments, to KeySend payments. This allows receivers to fail back stuck HTLCs and free up slots without waiting for a full CLTV expiry.