fix variable interpolation in service description

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

systems/palatine-hill/postgresql.nix

@@ -19,6 +19,9 @@ in
       enable = true;
       enableJIT = true;
       package = pkgs.postgresql_16;
+      configurePgStatStatements = true;
+      enableAllPreloadedLibraries = true;
+      preloadAllExtensions = true;
       identMap = ''
         # ArbitraryMapName systemUser DBUser
            superuser_map      root      postgres
@@ -68,7 +71,7 @@ in
         #random_page_cost = 1.25; # speed of random disk access relative to sequential access (1.0);
 
         # Monitoring;
-        shared_preload_libraries = "pg_stat_statements,auto_explain"; # per statement resource usage stats & log explain statements for slow queries
+        #shared_preload_libraries = "pg_stat_statements,auto_explain"; # per statement resource usage stats & log explain statements for slow queries
         track_io_timing = "on"; # measure exact block IO times;
         track_functions = "pl"; # track execution times of pl-language procedures if any;
         # Replication;