Reworked for simplified flake

modules/postgresql/default.nix

@@ -0,0 +1,19 @@
+{ config, lib, pkgs, specialConfig, ... }:
+{
+  # Disable local postgres (so NixOS won't start or manage it)
+  services = {
+      postgresql = {
+      enable = true;
+      ensureDatabases = [ "nbxplorermainnet" "btcpaydb" ];
+      ensureUsers = [
+        { name = "nbxplorer"; ensureDBOwnership = true; }
+        { name = "btcpay"; ensureDBOwnership = true; }
+      ];
+      authentication = ''
+        local all        all                      trust
+        host  all        all     0.0.0.1/32     trust
+        host  all        all     ::1/128          trust
+      '';
+    };
+  };
+}