nixos/homepage-dashboard: Set ALLOWED_HOSTS env var. (#399179)

- `programs.clash-verge.tunMode` was deprecated and removed because now service mode is necessary to start program. Without `programs.clash-verge.enable`, clash-verge-rev will refuse to start.

- `services.homepage-dashboard` now requires the `allowedHosts` option to be set in accordance with the [documentation](https://gethomepage.dev/installation/#homepage_allowed_hosts).

- `services.netbird.tunnels` was renamed to [`services.netbird.clients`](#opt-services.netbird.clients),

  hardened (using dedicated less-privileged users) and significantly extended.

  lib,

  ...

}:

let

  cfg = config.services.homepage-dashboard;

  # Define the settings format used for this program

        description = "Port for Homepage to bind to.";

      };

      allowedHosts = lib.mkOption {

        type = lib.types.str;

        default = "localhost:8082,127.0.0.1:8082";

        example = "example.com";

        description = ''

          Hosts that homepage-dashboard will be running under.

          You will want to change this in order to acess homepage from anything other than localhost.

          see the upsream documentation:

          <https://gethomepage.dev/installation/#homepage_allowed_hosts>

        '';

      };

      environmentFile = lib.mkOption {

        type = lib.types.str;

        description = ''

        NIXPKGS_HOMEPAGE_CACHE_DIR = "/var/cache/homepage-dashboard";

        PORT = toString cfg.listenPort;

        LOG_TARGETS = "stdout";

        HOMEPAGE_ALLOWED_HOSTS = cfg.allowedHosts;

      };

      serviceConfig = {