sync: short-hex Debug for peer from

[cbenhagen]

Description

Remote peer identity in Debug for InsertOrigin::Sync and Event::RemoteInsert was printed as a [u8; 32] integer list, unlike other logs that use compact hex. This switches those fields to derive_more::Debug with hex::encode of the first 5 bytes, matching iroh_base::PublicKey::fmt_short() / EndpointId logging style.

Also updates the PeerIdBytes doc line to refer to EndpointId, and refreshes the TODO to suggest iroh::EndpointId (re-exported from iroh-base) instead of outdated PeerId / iroh-net wording.

Breaking Changes

None.

Notes & open questions

Using iroh::EndpointId instead of PeerIdBytes ([u8; 32]) would be a breaking public API change but give us stronger typing, validation and built-in helpers (fmt_short, etc.). Happy to open a follow-up PR with that.

Change checklist

• Self-review.
• Documentation updates following the style guide, if relevant.
• Tests if relevant.
• All breaking changes documented.

[dignifiedquire]

thanks