Adds a SubscribeStatus gRPC RPC that pushes a fresh FullStatus snapshot
on every peer-recorder state change, replacing the Wails UI's 2-second
Status poll. The daemon's notifier already triggers on Connected /
Disconnected / Connecting / management or signal flip / address
change / peers-list change; we now coalesce those into ticks on a
buffered chan and stream the resulting snapshots over gRPC.
- Status recorder gains SubscribeToStateChanges /
UnsubscribeFromStateChanges + a non-blocking notifyStateChange that
drops ticks when a subscriber's 1-slot buffer is full (next snapshot
the consumer pulls already reflects everything).
- Server.Status handler split: the snapshot composition is shared
with the new SubscribeStatus stream handler so unary and stream
paths return identical bytes.
- UI peers service: pollLoop replaced by statusStreamLoop. The local
name of the existing SubscribeEvents loop is now toastStreamLoop so
the two streams are easy to tell apart — the underlying RPC name is
unchanged.
- Tray applyStatus skips the icon refresh when connected/lastStatus
hasn't changed; rapid SubscribeStatus bursts during health probes
no longer churn Shell_NotifyIcon or the log.