refactor(modules): make sure nothing is added without setting enable

modules/server/tailscale/default.nix

@@ -0,0 +1,52 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkIf;
+  inherit (config.networking) hostName;
+
+  cfg = config.roles.server;
+in {
+  config = mkIf (cfg.enable && cfg.tailscale.enable) {
+    services = {
+      tailscale = {
+        enable = true;
+        # TODO: add authKeyFile to get extraUpFlags to work
+        # https://github.com/juanfont/headscale/issues/1550
+        # https://github.com/juanfont/headscale/blob/main/docs/running-headscale-linux-manual.md#register-machine-using-a-pre-authenticated-key
+        # https://www.reddit.com/r/NixOS/comments/18kz1nb/tailscale_extraupflags_not_working/
+        extraUpFlags = [
+          "--login-server https://headscale.nelim.org"
+          "--operator=${cfg.user}"
+        ];
+      };
+    };
+
+    home-manager.users.${cfg.user} = {
+      programs.bash.shellAliases = {
+        # Connect to headscale
+        tup = "tailscale up --login-server https://headscale.nelim.org";
+
+        # Desktop
+        pc = "ssh -t matt@binto 'tmux -2u new -At ${hostName}'";
+
+        # NAS
+        nos = "ssh -t matt@nos 'tmux -2u new -At ${hostName}'";
+
+        # Experimenting server
+        servivi = "ssh -t matt@servivi 'tmux -2u new -At ${hostName}'";
+
+        # Home-assistant
+        homie = "ssh -t matt@homie 'tmux -2u new -At ${hostName}'";
+
+        # Cluster nodes
+        thingone = "ssh -t matt@thingone 'tmux -2u new -At ${hostName}'";
+        thingtwo = "ssh -t matt@thingtwo 'tmux -2u new -At ${hostName}'";
+      };
+    };
+  };
+
+  # For accurate stack trace
+  _file = ./default.nix;
+}