timelock_recovery: open issues

[accumulator]

Description

Timelock recovery currently can leave wallet balance out of the recovery process

• frozen coins/addresses are excluded; there should be a clear warning presented to the user, or alternatively the frozen balance should be included in the recovery.
• existing balances in lightning channels are excluded; the user should also be warned about this.

Also, the recovery recipient accepts addresses from the wallet itself, maybe this should be prevented as it defeats the purpose.

[accumulator]

Also note that silent payment addresses should be considered invalid for use in timelock recovery after #9900 gets merged.

[jfitie]

• When creating the timelock transactions, 2 addresses in the wallet are labeled 'Timelock Recovery Alert Address' and 'Timelock Recovery Cancellation Address'. However these are normal addresses and will be used next when creating a receive request. They should be blocked or skipped somehow.

[jfitie]

• frozen coins/addresses are excluded; there should be a clear warning presented to the user, or alternatively the frozen balance should be included in the recovery.

One could even argue the opposite approach: include only frozen coins in the active wallet when creating the Timelock Recovery plan. This provides a safer method for generating the plan, as there's no risk of accidentally spending any included UTXOs, which would invalidate the plan.

In this setup, unfrozen UTXOs/addresses are excluded from the backup, which is appropriate, since they represent spendable funds.

The website mentions: "Therefore it is highly recommended not to use the wallet for daily purposes after creating a Timelock Recovery plan".
However, this precaution becomes unnecessary if only frozen coins are used in the Timelock Recovery plan.