Two fixes for missing recovery/resolved notifications:
1. API config PUT handler now preserves notifyOnResolve when the client
omits it from the request body. Go decodes a missing bool as false,
which silently disabled recovery notifications on older clients.
2. CancelAlert now always cleans up the cooldown record even when the
alert has already left the pending buffer, preventing stale cooldown
entries from suppressing future alert cycles.
rcourtman
9b531c547d