auth01: decommission host and remove authelia/lldap services

Remove auth01 host configuration and associated services in preparation
for new auth stack with different provisioning system.

Removed:
- hosts/auth01/ - host configuration
- services/authelia/ - authelia service module
- services/lldap/ - lldap service module
- secrets/auth01/ - sops secrets
- Reverse proxy entries for auth and lldap
- Monitoring alert rules for authelia and lldap
- SOPS configuration for auth01

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

flake.nix

@@ -246,22 +246,6 @@
             sops-nix.nixosModules.sops
           ];
         };
-        auth01 = nixpkgs.lib.nixosSystem {
-          inherit system;
-          specialArgs = {
-            inherit inputs self sops-nix;
-          };
-          modules = [
-            (
-              { config, pkgs, ... }:
-              {
-                nixpkgs.overlays = commonOverlays;
-              }
-            )
-            ./hosts/auth01
-            sops-nix.nixosModules.sops
-          ];
-        };
         testvm01 = nixpkgs.lib.nixosSystem {
           inherit system;
           specialArgs = {