fail hard on invalid config file instead of warning and using defaults

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: b0bbywan

config/config.go

@@ -303,13 +303,8 @@ func New(cfgFile *string) (*Config, error) {
 	viper.SetConfigType("yaml") // config file format
 
 	if err := readConfig(cfgFile); err != nil {
-		// If user explicitly provided a config file, fail hard on any error
-		if cfgFile != nil && *cfgFile != "" {
-			return nil, fmt.Errorf("failed to read config file: %w", err)
-		}
-		// Otherwise, only warn for non-file-not-found errors
 		if _, isNotFound := err.(viper.ConfigFileNotFoundError); !isNotFound {
-			logger.Warn("failed to read config: %v", err)
+			return nil, fmt.Errorf("failed to read config file: %w", err)
 		}
 	}