fix: convert fridge banner newlines to \r\n for terminal display

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

internal/shell/fridge/fridge.go

@@ -30,8 +30,9 @@ func (f *FridgeShell) Handle(ctx context.Context, sess *shell.SessionContext, rw
 
 	state := newFridgeState()
 
-	// Boot banner.
-	fmt.Fprint(rw, bootBanner())
+	// Boot banner — convert \n to \r\n for terminal display.
+	banner := strings.ReplaceAll(bootBanner(), "\n", "\r\n")
+	fmt.Fprint(rw, banner)
 
 	for {
 		if _, err := fmt.Fprint(rw, "FridgeOS> "); err != nil {