feat(MOMO): setup syncthing and vaultwarden

hosts/MOMO/services/postgresql.nix

@@ -0,0 +1,26 @@
+{ ... }:
+{
+
+  services.postgresql = {
+    enable = true;
+    ensureDatabases = [ "vaultwarden" ];
+
+    ensureUsers = [
+      {
+        name = "vaultwarden";
+        ensureDBOwnership = true;
+      }
+    ];
+
+    # type   database     DBuser  auth-method  mapping
+    authentication = ''
+      local  vaultwarden  all     ident        map=vaultwarden-users
+    '';
+
+    # name               sysuser        dbuser
+    identMap = ''
+      vaultwarden-users  vaultwarden    vaultwarden
+    '';
+  };
+
+}