Since channeld handles splicing, it makes sense that it knows the opening feerate now. This is needed for rounding out splice script errors and logging.

On the rare chance a channel id starts with 02 or 03 we need to check of it’s referring to a channel before parsing it node id, instead of after.

Here we update `psbt_input_get_weight` to allow the caller to specify what kind of input size estimation they would like. Before it was just “zero witness bytes” which we now move to the default behavior and add an assumption option for P2WSH -> 2of2 multisig which is what we typically see in splicing.

At the same time we move channeld over to using the opening feerate estimation instead of the less useful “max feerate.” We make splice script use this same feerate.

After auditing the feerates for these two places against each other and the actually created transaction, we implement some fixes making them all match.

While we’re here, we add relevant debug log messages.

Changelog-Changed: Audited and updated splice’s feerate calculations to be precise to the byte — a critical change to accomodate splice script.

When using wetlog we might not also have debug log enabled.

In some splice script failure modes, some memory is leaked.

These don’t occur in normal operation — just when an error occurs.

This cleans up those memory leaks.

Enable feerate checks for the test now that they’re working well