convert mount service to trigger

Good: this means it's not hanging holding the s6 dataase lock.

Bad: it's the ugliest implementation and doesn't deserve to be preserved

(tbf the ugliness is not new)

tests/inout/configuration.nix

@@ -0,0 +1,61 @@
+{ config, pkgs, lib, modulesPath, ... } :
+let
+  inherit (pkgs.liminix.services) bundle oneshot longrun;
+  inherit (pkgs.pseudofile) dir symlink;
+  inherit (pkgs) serviceFns;
+
+  svc = config.system.service;
+
+in rec {
+  imports = [
+    "${modulesPath}/dhcp6c"
+    "${modulesPath}/dnsmasq"
+    "${modulesPath}/firewall"
+    "${modulesPath}/hostapd"
+    "${modulesPath}/network"
+    "${modulesPath}/ssh"
+    "${modulesPath}/mount"
+  ];
+
+  filesystem = dir { srv = dir {}; };
+
+  kernel = {
+    config = {
+      USB = "y";
+      USB_EHCI_HCD = "y";
+      USB_EHCI_HCD_PLATFORM = "y";
+      USB_OHCI_HCD = "y";
+      USB_OHCI_HCD_PLATFORM = "y";
+      USB_SUPPORT = "y";
+      USB_COMMON = "y";
+      USB_STORAGE = "y";
+      USB_STORAGE_DEBUG = "n";
+      USB_UAS = "y";
+      USB_ANNOUNCE_NEW_DEVICES = "y";
+      SCSI = "y";
+      BLK_DEV_SD = "y";
+      USB_PRINTER = "y";
+      MSDOS_PARTITION = "y";
+      EFI_PARTITION = "y";
+      EXT4_FS = "y";
+      EXT4_USE_FOR_EXT2 = "y";
+      FS_ENCRYPTION = "y";
+    };
+  };
+
+  rootfsType = "jffs2";
+  hostname = "inout";
+
+  services.mount_external_disk = svc.mount.build {
+    device = "LABEL=backup-disk";
+    mountpoint = "/srv";
+    fstype = "ext4";
+  };
+
+  services.sshd = svc.ssh.build { };
+
+  defaultProfile.packages = with pkgs; [
+    min-collect-garbage
+    tcpdump
+  ];
+}