There is this article Running on a Transparent pfSense Bridge which is a bit out of date. Mainly it needs to be updated to have an example of using v4, and also it should be using the bridge filtering tunables talked about in Bridging and firewalling | pfSense Documentation
I would set net.link.bridge.pfil_member to 0 and net.link.bridge.pfil_bridge to 1. And then it should be a fairly simple matter of making the bridge interface the LAN (and listening) interface, and the firewall rules would be created on the bridge interface. The member interface(s) can basically be ignored.
Using the UniFi IDS should not be a problem, but I have not tested VLANs. Because the bridge is on VLAN1, I’m not entirely sure the ideal method to have VLANs use adam:ONE for DNS. It might be possible to have all the VLANs use the bridge interface IP, you’d have to try it.