Single switch, yes. Personally I would probably aim for a managed (must have for vlan support) switch with at least 16 ports where 8 has PoE+ (Power over Ethernet) with at least 100W total budget. The goal would be to power access points and that security camera through PoE instead of separate psus.
A cheaper alternative is to skip PoE for now and buy an 8-port managed switch now and a secondary PoE switch in the future if need be.
There are access points with VLAN support, so you can have an access point deliver multiple SSIDs that belong to different VLANs. Two things to look for here is Local Management and PoE powered. You don't want your access points to become paper weights when the cloud management system is shut down. I don't want to use cloud management at all to be honest.
PoE allows you to protect your camera and your APs with the same UPS you put in to protect your network rack.
Draw up some plans beforehand, quick example where I forgot your video doorbell that would be on a separate SSID/VLAN through the APs if it uses WiFi. Which is kind of the point with drawing it up. It helps you find out what you missed.
edit: And that is just an example on how to draw it up. I imagine you want your security camera and doorbell to save video on the NAS, so then their vlan need to be able to communicate with the NAS vlan, as another example of missing stuff in the drawing.
This is such an epic post. I am super grateful. I was definitely thinking about a POE switch because it just makes sense to me that you'd have the network power what it can rather than have to monitor batteries.
Talking of which, I hope we get Power Over Thread coming to Matter 2.0. That would be glorious. It wouldn't even need a lot of power, just enough to keep motion sensors topped up.
One managed handles all the VLAN designations and most of the heavy lifting of the network,
One is just a virtual switch in my Proxmox server dealing with the virtual machines and containers.
And then a physical VLAN aware switch at each end of the house for all client devices on multiple VLANS, ie CCTV (no internet), Media VMs on VPN only VLAN, PC, laptop, phones etc on their own, and a management VLAN.
My main need of a separate POE is more logistical than networking, it's convenient to power a couple of cameras from a distant switch.
I think if I started over the only things I'd alter would be the number of ports on the main switch. 16 ports at least. I've used all 8 and still have things I would use more for.
Here's a physical diagram (not all clients are shown) that may help some more: