Add NixOS module for full agregators stack with VM test

Module manages PostgreSQL (both databases + schema init), qBittorrent
(VPN-confined via VPN-Confinement), Jackett, metadata-agregator,
musicfs, and the main orchestrator. All services are independently
enableable with auto-wired inter-service configuration.

Includes NixOS VM test validating PostgreSQL setup, schema
initialization, service startup, and directory creation.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/claude-agent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

flake.nix

@@ -3,6 +3,7 @@
     nixpkgs.url = "github:nixos/nixpkgs";
     flake-parts.url = "github:hercules-ci/flake-parts";
     git-hooks.url = "github:cachix/git-hooks.nix";
+    vpnconfinement.url = "github:Maroka-chan/VPN-Confinement";
   };
 
   outputs =
@@ -18,6 +19,18 @@
         "x86_64-linux"
       ];
 
+      flake = {
+        nixosModules = {
+          agregators = {
+            imports = [
+              ./nix/default.nix
+              inputs.vpnconfinement.nixosModules.default
+            ];
+          };
+          default = self.nixosModules.agregators;
+        };
+      };
+
       perSystem =
         {
           system,
@@ -49,6 +62,9 @@
 
           checks = {
             inherit pre-commit-check;
+            simple-test = pkgs.callPackage ./tests/simple-test.nix {
+              nixosModules = self.nixosModules;
+            };
           };
 
           devShells.default = pkgs.mkShell {