Revert "nixos/home/routing-common: Move Tailscale to home routers"

This reverts commit 7c05b6158f.

nixos/boxes/britway/tailscale.nix

@@ -1,5 +1,6 @@
 { lib, pkgs, config, assignments, allAssignments, ... }:
 let
+  inherit (lib) concatStringsSep;
   inherit (lib.my.c) pubDomain;
   inherit (lib.my.c.britway) prefixes domain;
 
@@ -19,6 +20,10 @@ let
     });
   });
 
+  advRoutes = concatStringsSep "," [
+    lib.my.c.home.prefixes.all.v4
+    lib.my.c.home.prefixes.all.v6
+  ];
   pubNameservers = [
     "1.1.1.1"
     "1.0.0.1"
@@ -85,6 +90,7 @@ in
           "--login-server=https://hs.nul.ie"
           "--netfilter-mode=off"
           "--advertise-exit-node"
+          "--advertise-routes=${advRoutes}"
           "--accept-routes=false"
         ];
       };