nullclaw: add utils, nix eval cache tmpfs

flake.nix

@@ -12,7 +12,8 @@
 			url = "github:microvm-nix/microvm.nix";
 			inputs.nixpkgs.follows = "nixpkgs";
 		};
-		nullclaw.url = "github:illustris/nullclaw?ref=sqlite-on-9p";
+		# nullclaw.url = "github:illustris/nullclaw?ref=sqlite-on-9p";
+		nullclaw.url = "path:///home/illustris/src/nullclaw";
 		nix-mcp.url = "github:illustris/nix-mcp";
 	};
 
@@ -154,14 +155,22 @@
 				mem = 4096;
 				extraModules = [({ pkgs, ... }: {
 					imports = [ self.nixosModules.storeOverlay ];
-					fileSystems."/root" = {
-						device = "/var/lib/nullclaw";
-						options = [ "bind" ];
+					fileSystems = {
+						"/root" = {
+							device = "/var/lib/nullclaw";
+							options = [ "bind" ];
+						};
+						"/root/.cache/nix" = {
+							fsType = "tmpfs";
+							options = [ "size=1G" "mode=0700" ];
+						};
 					};
 					environment.systemPackages = with pkgs; [
 						nullclaw.packages.${system}.default
 						tmux
 						git
+						strace
+						bpftrace
 					];
 				})];
 			};