system: enable homelab-deploy listener for all vault hosts

Add system/homelab-deploy.nix module that automatically enables the
listener on all hosts with vault.enable=true. Uses homelab.host.tier
and homelab.host.role for NATS subject subscriptions.

- Add homelab-deploy access to all host AppRole policies
- Remove manual listener config from vaulttest01 (now handled by system module)

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

system/default.nix

@@ -3,6 +3,7 @@
   imports = [
     ./acme.nix
     ./autoupgrade.nix
+    ./homelab-deploy.nix
     ./monitoring
     ./motd.nix
     ./packages.nix

system/homelab-deploy.nix

@@ -0,0 +1,31 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.vault;
+  hostCfg = config.homelab.host;
+in
+{
+  config = lib.mkIf cfg.enable {
+    # Fetch listener NKey from Vault
+    vault.secrets.homelab-deploy-nkey = {
+      secretPath = "shared/homelab-deploy/listener-nkey";
+      extractKey = "nkey";
+    };
+
+    # Enable homelab-deploy listener
+    services.homelab-deploy.listener = {
+      enable = true;
+      tier = hostCfg.tier;
+      role = hostCfg.role;
+      natsUrl = "nats://nats1.home.2rjus.net:4222";
+      nkeyFile = "/run/secrets/homelab-deploy-nkey";
+      flakeUrl = "git+https://git.t-juice.club/torjus/nixos-servers.git";
+    };
+
+    # Ensure listener starts after vault secret is available
+    systemd.services.homelab-deploy-listener = {
+      after = [ "vault-secret-homelab-deploy-nkey.service" ];
+      requires = [ "vault-secret-homelab-deploy-nkey.service" ];
+    };
+  };
+}