fix(tui): preserve newlines in user messages by bypassing glamour

cmd/sidekick-tui/main.go

@@ -220,6 +220,14 @@ func (m model) renderMessage(msg sidekick.Message) string {
   content := msg.Content
   reasoning := msg.Reasoning
 
+  // Handle user message specifically to preserve newlines
+  if msg.Role == sidekick.MessageRoleUser {
+    if m.width > 4 {
+      content = lipgloss.NewStyle().Width(m.width - 4).Render(content)
+    }
+    return label + "\n" + content
+  }
+
   // If this is the banner message, handle it specially to preserve ASCII art
   if strings.Contains(content, "----") && msg.Role == sidekick.MessageRoleSystem {
     if strings.HasPrefix(content, banner) {