Fix cloudflared service with preStart script to ensure log directory and file exist

desktop/ftl.host.nix

@@ -26,6 +26,13 @@ in {
     wants = [ "network-online.target" ];
     wantedBy = [ "multi-user.target" ];
 
+    # Create directory for log files
+    preStart = ''
+      mkdir -p "$(dirname ${tunnel.logPath})"
+      touch ${tunnel.logPath}
+      chmod 644 ${tunnel.logPath}
+    '';
+
     serviceConfig = {
       ExecStart = "${pkgs.cloudflared}/bin/cloudflared access tcp --hostname ${tunnel.remoteHost} --url ${tunnel.remoteTarget} --port ${toString tunnel.localBindPort} --logfile ${tunnel.logPath}";
       Restart = "always";