i3: Move kitty daemonization into own script

.config/i3/config

@@ -36,18 +36,11 @@ set $TERM_CMD_FLAG
 # a single sprite cache on the GPU"[^1], so that startup is almost instant.
 #
 # For this to work best, launch one hidden "daemon" instance at startup so that
-# the kitty process is always running, even when no OS windows exists.
+# the kitty process is always running, even when no OS windows exists. See the
-#
+# daemon.sh script in .config/kitty.
-# NOTE: `--start-as hidden` needs kitty 0.42.0 or later.
-#
-# Additionally allow remote_control over a socket, so that kitty-cwd works.
 #
 # [^1]: kitty(1)
-exec --no-startup-id $TERMINAL \
+exec --no-startup-id kitty-daemon
-	--start-as hidden \
-	--detach \
-	-o allow_remote_control=socket-only \
-	--listen-on unix:/tmp/mykitty
 
 # Multi monitor support
 exec_always --no-startup-id ~/.config/i3/monitor-setup.sh &

.config/kitty/daemon.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Julian Prein
+#
+# Daemonize kitty by launching one hidden instance that new invocations can use
+# to create new OS windows. This makes kitty startup a lot faster since all
+# windows can now share a single CPU process and GPU sprite cache. Additionally
+# allow remote_control over a socket, so that kitty-cwd works.
+#
+# To launch new invocations using the daemon created by this script use:
+#
+#     kitty --single-instance
+#
+# NOTE: `--start-as hidden` needs kitty 0.42.0 or later.
+
+kitty \
+	--single-instance \
+	--start-as hidden \
+	--detach \
+	-o allow_remote_control=socket-only \
+	--listen-on unix:/tmp/mykitty

.local/bin/kitty-daemon

@@ -0,0 +1 @@
+../../.config/kitty/daemon.sh