Add a worked example walking through the recovery flow on testnet

[chillwur]

Description

Once implemented, the multi-step recovery flow (request -> wait -> confirm) especially benefits from a single worked example.

Deliverables

• A walkthrough showing request_recovery, advancing past the timelock on testnet (i.e. waiting), then confirm_recovery, with expected output at each step.

Depends on

Implement confirm_recovery(phone_hash) entrypoint that rebinds after the timelock