style: change name from pg to db for nix just cmds

justfile

@@ -560,10 +560,10 @@ secrets:
 	@cd lib/mix/tasks/secrets/ && mix escript.build && ./secrets 128 3
 
 # Start or stop nix postgres server
-@nix-pg pg_cmd:
+@nix-db pg_cmd:
   pg_ctl -D ${PGDATA} -l ${PGDATA}/all.log -o "--unix_socket_directories='${PGDATA}'" $pg_cmd
 
 # Initialize postgres database. Only need to run the first time!
-nix-pg-init: (nix-pg "start")
+nix-db-init: (nix-db "start")
   createdb ${PGDATABASE}
   createuser -dlsw ${PGUSERNAME}