Add XDG_CONFIG_DIRS and XDG_DATA_DIRS to split environment variables

These XDG variables contain colon-separated paths similar to PATH and
MANPATH. Split them on ':' and display each path on a separate line
for better readability in table output.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: oalders

known.go

@@ -25,10 +25,12 @@ import (
 )
 
 const (
-	manpath  = "MANPATH"
-	path     = "PATH"
-	trueStr  = "true"
-	falseStr = "false"
+	manpath       = "MANPATH"
+	path          = "PATH"
+	xdgConfigDirs = "XDG_CONFIG_DIRS"
+	xdgDataDirs   = "XDG_DATA_DIRS"
+	trueStr       = "true"
+	falseStr      = "false"
 )
 
 // Run "is known ...".
@@ -325,7 +327,7 @@ func envSummary(ctx *types.Context, asJSON bool, asMarkdown bool) error {
 
 		name, value := parts[0], parts[1]
 
-		if name == path || name == manpath {
+		if name == path || name == manpath || name == xdgConfigDirs || name == xdgDataDirs {
 			pathParts := strings.Split(value, ":")
 			if asJSON {
 				envMap[name] = pathParts
@@ -369,7 +371,7 @@ func getEnv(ctx *types.Context, name string, asJSON bool) (string, error) {
 	values := []string{}
 
 	switch {
-	case set && (name == path || name == manpath):
+	case set && (name == path || name == manpath || name == xdgConfigDirs || name == xdgDataDirs):
 		values = strings.Split(value, ":")
 	case set:
 		values = append(values, value)