Ash-L2L

>Not sure about the MSRV bump, we follow [rust-bitcoin's](https://github.com/rust-bitcoin/rust-bitcoin?tab=readme-ov-file#minimum-supported-rust-version-msrv) for ecosystem compatibility. Updated to only bump rust version for the CI tests. The version bump is only required for dev-dependencies,...

>Do you need the wallet to be able to sync up to a specific blockhash? Or is syncing up to a block height good enough? Syncing to a specific blockhash...

@erikjohnston Can you update this branch/PR? `ouroboros_macro v0.18.0` depends on `proc-macro-error v1.0.4`, for which there is a security advisory https://rustsec.org/advisories/RUSTSEC-2024-0370