hosts: decommission ca host and remove labmon

Remove the step-ca host and labmon flake input now that ACME has been
migrated to OpenBao PKI.

Removed:
- hosts/ca/ - step-ca host configuration
- services/ca/ - step-ca service module
- labmon flake input and module (no longer used)

Updated:
- flake.nix - removed ca host and labmon references
- flake.lock - removed labmon input
- rebuild-all.sh - removed ca from host list
- CLAUDE.md - updated documentation

Note: secrets/ca/ should be manually removed by the user.

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

flake.nix

@@ -13,10 +13,6 @@
       url = "git+https://git.t-juice.club/torjus/alerttonotify?ref=master";
       inputs.nixpkgs.follows = "nixpkgs-unstable";
     };
-    labmon = {
-      url = "git+https://git.t-juice.club/torjus/labmon?ref=master";
-      inputs.nixpkgs.follows = "nixpkgs-unstable";
-    };
     nixos-exporter = {
       url = "git+https://git.t-juice.club/torjus/nixos-exporter";
       inputs.nixpkgs.follows = "nixpkgs-unstable";
@@ -34,7 +30,6 @@
       nixpkgs-unstable,
       sops-nix,
       alerttonotify,
-      labmon,
       nixos-exporter,
       homelab-deploy,
       ...
@@ -50,7 +45,6 @@
       commonOverlays = [
         overlay-unstable
         alerttonotify.overlays.default
-        labmon.overlays.default
       ];
       # Common modules applied to all hosts
       commonModules = [
@@ -131,15 +125,6 @@
             ./hosts/http-proxy
           ];
         };
-        ca = nixpkgs.lib.nixosSystem {
-          inherit system;
-          specialArgs = {
-            inherit inputs self sops-nix;
-          };
-          modules = commonModules ++ [
-            ./hosts/ca
-          ];
-        };
         monitoring01 = nixpkgs.lib.nixosSystem {
           inherit system;
           specialArgs = {
@@ -147,7 +132,6 @@
           };
           modules = commonModules ++ [
             ./hosts/monitoring01
-            labmon.nixosModules.labmon
           ];
         };
         jelly01 = nixpkgs.lib.nixosSystem {