fix: ScopedIp considered Eq when interface_ids change

[keepsimple1]

This is to fix issue #445 .

• ScopedIpV4 previously had custom Eq/Hash impls that only compared addr, ignoring interface_ids. This meant consumers comparing HashSet across resolve events could not detect when new interfaces were added for the same IPv4 address, and HashSet::insert would silently discard updates.
• Replaced custom impls with derived Eq, PartialEq, and Hash so interface_ids is included in equality and hashing.
• Updated the daemon's address merge logic to use a linear scan by IP (instead of HashSet::take) since take no longer matches entries with different interface_ids.