kitty:get_cwd: Use the match flag for performance

Instead of requesting the full tree as a JSON and extracting the focused
window with `jq`, use `kitten-@-ls`'s `--match` flag. This further
improves the performance.

Also remove the commented code using recursive descent because it is not
up-to-date anymore.

.config/kitty/get_cwd.sh

@@ -11,23 +11,10 @@ socket_path="${TMPDIR:-/tmp}/kitty.$USER/kitty${1:+-$1}.sock"
 
 # NOTE: Unfortunately kitten-@-ls(1) is slow, so communicate with the socket
 #       directly.
-# NOTE: the backticks are used for hacky line-continuation, taken from
-#       https://stackoverflow.com/a/7729087/2092762c9
-printf '\eP@kitty-cmd{"cmd":"ls","version":[0,26,0]}\e\\' \
+printf '\eP@kitty-cmd{%s,%s,%s}\e\\' \
+	'"cmd":"ls"' \
+	'"version":[0,26,0]' \
+	'"payload":{"match":"state:focused"}' \
 | nc -U -q0 "$socket_path" \
 | awk '{ print substr($0, 13, length($0) - 14) }' \
-| jq -er ".data`
-	` | fromjson`
-	` | .[]`
-	` | select(.is_focused).tabs.[]`
-	` | select(.is_focused).windows.[]`
-	` | select(.is_focused).cwd"
-
-# An alternative version that uses recursive descent to find focused objects
-# that also have a `.cwd` key:
-#
-#	| jq -er "..`
-#		` | objects`
-#		` | select(.is_focused)`
-#		` | to_entries.[]`
-#		` | select(.key == \"cwd\").value"
+| jq -er ".data | fromjson | .[].tabs.[].windows.[].cwd"