wide idol
The tailscale container would only handle tailscale traffic. There's no way for it to proxy traffic coming in directly to the container itself via the host (not via the tailnet).
You can achieve what you're after, but you'll want to expose the AdGuard container itself to the host and make sure the port is also open on your hosts firewall.
You'd then end up with these two paths:
Mobile device with tailscale -> Tailnet -> Tailscale container -> AdGuard container
LAN device (or wan, if you've exposed this publicly with a public ip address) -> Host machine -> AdGuard container
full haven