Update flake with postgres server

flake.nix

@@ -41,6 +41,10 @@
         echo "Launching misael"
         ${jdk}/bin/java -jar ${misael}/misael.jar --spring.datasource.url=$MISAEL_DATABASE --spring.datasource.password=$MISAEL_PASSWORD "$@"
       '';
+      postgres-server = pkgs.writeShellScriptBin "postgres-server" ''
+            mkdir -p .postgres
+            ${pkgs.podman}/bin/podman run -e POSTGRES_USER=misael -e POSTGRES_PASSWORD=misael-dev -e POSTGRES_DB=misael --volume ./.postgres:/var/lib/postgresql -p 127.0.0.1:5432:5432 postgres:18.4 & > .postgres/postgres.log &
+      '';
     in {
       packages.${system} = {
         default = self.packages.${system}.misael;
@@ -50,6 +54,7 @@
       apps.${system} = {
         default = self.apps.${system}.misael;
         misael = { type = "app"; program = "${misael-launcher}/bin/misael"; };
+        postgres-server = { type = "app"; program = "${postgres-server}/bin/postgres-server"; };
       };
 
       devShells.${system} = {