feat: add receiver rate limiting (refs #64)

internal/config/config.go

@@ -175,35 +175,27 @@ func envDuration(
 	return d, nil
 }
 
-// resolveEnvironment reads WEBHOOKER_ENVIRONMENT, defaulting to
-// dev, and rejects unrecognised values.
-func resolveEnvironment() (string, error) {
-	environment := os.Getenv("WEBHOOKER_ENVIRONMENT")
-	if environment == "" {
-		environment = EnvironmentDev
-	}
-
-	if environment != EnvironmentDev &&
-		environment != EnvironmentProd {
-		return "", fmt.Errorf(
-			"%w: WEBHOOKER_ENVIRONMENT must be '%s' or '%s', got '%s'",
-			ErrInvalidEnvironment,
-			EnvironmentDev, EnvironmentProd, environment,
-		)
-	}
-
-	return environment, nil
-}
-
 // New creates a Config by reading environment variables.
 //
 //nolint:revive // lc parameter is required by fx even if unused.
 func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
 	log := params.Logger.Get()
 
-	environment, err := resolveEnvironment()
-	if err != nil {
-		return nil, err
+	// Determine environment from WEBHOOKER_ENVIRONMENT env var,
+	// default to dev
+	environment := os.Getenv("WEBHOOKER_ENVIRONMENT")
+	if environment == "" {
+		environment = EnvironmentDev
+	}
+
+	// Validate environment
+	if environment != EnvironmentDev &&
+		environment != EnvironmentProd {
+		return nil, fmt.Errorf(
+			"%w: WEBHOOKER_ENVIRONMENT must be '%s' or '%s', got '%s'",
+			ErrInvalidEnvironment,
+			EnvironmentDev, EnvironmentProd, environment,
+		)
 	}
 
 	// Parse the retention sweep interval; a set-but-unparseable value