* [client] Batch macOS DNS domains across multiple scutil keys to avoid truncation
scutil has undocumented limits: 99-element cap on d.add arrays and ~2048
byte value buffer for SupplementalMatchDomains. Users with 60+ domains
hit silent domain loss. This applies the same batching approach used on
Windows (nrptMaxDomainsPerRule=50), splitting domains into indexed
resolver keys (NetBird-Match-0, NetBird-Match-1, etc.) with 50-element
and 1500-byte limits per key.
* check for all keys on getRemovableKeysWithDefaults
* use multi error
