Fix AtlasChat crash: guard renderContent and message render against null content

Made-with: Cursor

components/AtlasChat.tsx

@@ -16,7 +16,8 @@ interface AtlasChatProps {
 // ---------------------------------------------------------------------------
 // Markdown-lite renderer — handles **bold**, newlines, numbered/bullet lists
 // ---------------------------------------------------------------------------
-function renderContent(text: string) {
+function renderContent(text: string | null | undefined) {
+  if (!text) return null;
   return text.split("\n").map((line, i) => {
     const parts = line.split(/(\*\*.*?\*\*)/g).map((seg, j) =>
       seg.startsWith("**") && seg.endsWith("**")
@@ -205,7 +206,8 @@ export function AtlasChat({ projectId }: AtlasChatProps) {
     }
   };
 
-  const isEmpty = messages.length === 0 && !isStreaming;
+  const visibleMessages = messages.filter(msg => msg.content);
+  const isEmpty = visibleMessages.length === 0 && !isStreaming;
 
   return (
     <div style={{
@@ -258,7 +260,7 @@ export function AtlasChat({ projectId }: AtlasChatProps) {
           >
             Reset
           </button>
-          {messages.map((msg, i) => (
+          {visibleMessages.map((msg, i) => (
             <MessageRow key={i} msg={msg} userInitial={userInitial} />
           ))}
           {isStreaming && <TypingIndicator />}