fix: log environment variable configuration loading when no config file is found

Signed-off-by: Deluan <deluan@navidrome.org>

conf/configuration.go

@@ -344,6 +344,8 @@ func Load(noConfigDump bool) {
 	// Log configuration source
 	if Server.ConfigFile != "" {
 		log.Info("Loaded configuration", "file", Server.ConfigFile)
+	} else if hasNDEnvVars() {
+		log.Info("No configuration file found. Loaded configuration only from environment variables")
 	} else {
 		log.Warn("No configuration file found. Using default values. To specify a config file, use the --configfile flag or set the ND_CONFIGFILE environment variable.")
 	}
@@ -502,6 +504,16 @@ func AddHook(hook func()) {
 	hooks = append(hooks, hook)
 }
 
+// hasNDEnvVars checks if any ND_ prefixed environment variables are set (excluding ND_CONFIGFILE)
+func hasNDEnvVars() bool {
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(env, "ND_") && !strings.HasPrefix(env, "ND_CONFIGFILE=") {
+			return true
+		}
+	}
+	return false
+}
+
 func setViperDefaults() {
 	viper.SetDefault("musicfolder", filepath.Join(".", "music"))
 	viper.SetDefault("cachefolder", "")