refactor(nix,postgres): update initial database setup to use structured configuration to improving readability and maintainability

Refactor the initial database setup to utilize a more structured approach with an array of initialDatabases, improving readability and maintainability.

Author: JakobLichterfeld

nix/module.nix

@@ -237,13 +237,14 @@ in
           inherit (cfg.postgres) port;
         };
 
-        initialScript = pkgs.writeText "teslamate-psql-init" ''
-          \set password `echo $DATABASE_PASS`
-          CREATE DATABASE ${cfg.postgres.database};
-          CREATE USER ${cfg.postgres.user} with encrypted password :'password';
-          GRANT ALL PRIVILEGES ON DATABASE ${cfg.postgres.database} TO ${cfg.postgres.user};
-          ALTER USER ${cfg.postgres.user} WITH SUPERUSER;
-        '';
+        initialDatabases = [{
+          name = cfg.postgres.database;
+          user = cfg.postgres.user;
+          pass = "\${DATABASE_PASS}";
+          initialSQL = lib.literalExpression ''
+            ALTER USER ${cfg.postgres.user} WITH SUPERUSER;
+          '';
+        }];
       };
 
       # Include secrets in postgres as well