Detect SSH sessions without affecting performance

Exclude local runs by KITTY_PID.
Check KITTY_WINDOW_ID to detect connections via ssh kitten.
Check SSH via who -m with the integration manually installed and sudo.

shell-integration/zsh/kitty-integration

@@ -233,8 +233,17 @@ _ksi_deferred_init() {
         # (LF becomes \n, etc.). This isn't necessary in precmd because (%) does it
         # for us.
         builtin local is_ssh_session="n"
-        if [[ -n "$SSH_TTY$SSH2_TTY" ]]; then
-            is_ssh_session="y";
+        if [[ -n "$KITTY_PID" ]]; then
+            # kitty running locally
+        elif [[ -n "$SSH_TTY" || -n "$SSH2_TTY$KITTY_WINDOW_ID" ]]; then
+            # connected to most SSH servers
+            # or use ssh kitten to connected to some SSH servers that do not set SSH_TTY
+            is_ssh_session="y"
+        elif [[ -n "$(builtin command -v who)" ]]; then
+            # the shell integration script is installed manually on the remote system
+            # the environment variables are cleared after sudo
+            # OpenSSH's sshd creates entries in utmp for every login so use those
+            [[ "$(builtin command who -m 2> /dev/null)" =~ "\([a-fA-F.:0-9]+\)$" ]] && is_ssh_session="y"
         fi
         
         if [[ "$is_ssh_session" == "y" ]]; then