Pass over a config path that runs through a file

Of the places pixa looks for its config file on its own, one whose path
runs through a file, such as under a HOME of /dev/null, aborted startup
with "not a directory", though no file can be there. It is now passed
over like a file that does not exist, as README.md says.

Model: opus-5-5

internal/config/config.go

@@ -15,6 +15,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"git.eeqj.de/sneak/smartconfig"
@@ -779,10 +780,12 @@ func loadConfigFile(log *slog.Logger, appName string) (*smartconfig.Config, erro
 	for _, path := range configPaths {
 		cleanPath := filepath.Clean(path)
 
-		// Only a config file that does not exist is skipped. One that
+		// Only a config file that does not exist is skipped, including
-		// cannot be read or does not parse is a fatal startup error.
+		// one whose path runs through a file, such as under a HOME of
+		// /dev/null. One that cannot be read or does not parse is a
+		// fatal startup error.
 		_, statErr := os.Stat(cleanPath)
-		if errors.Is(statErr, fs.ErrNotExist) {
+		if errors.Is(statErr, fs.ErrNotExist) || errors.Is(statErr, syscall.ENOTDIR) {
 			continue
 		}