Fix Atlas chat duplicate messages; add Reset button

- Add cleanup flag to useEffect to prevent state updates after unmount,
  eliminating the race condition on rapid navigation
- Add handleReset: calls DELETE endpoint, clears state, re-triggers greeting
- Add subtle "Reset" button (top-right of message area) so user can wipe
  polluted history and start fresh

Made-with: Cursor

components/AtlasChat.tsx

@@ -147,34 +147,50 @@ export function AtlasChat({ projectId }: AtlasChatProps) {
     }
   }, [projectId]);
 
-  // On mount: load stored history; if empty, trigger Atlas greeting
+  // On mount: load stored history; if empty, trigger Atlas greeting exactly once
   useEffect(() => {
-    if (historyLoaded) return;
+    let cancelled = false; // guard against unmount during fetch
 
     fetch(`/api/projects/${projectId}/atlas-chat`)
       .then(r => r.json())
       .then((data: { messages: ChatMessage[] }) => {
+        if (cancelled) return;
         const stored = data.messages ?? [];
         setMessages(stored);
         setHistoryLoaded(true);
 
-        // Only trigger greeting if there's genuinely no history yet
+        // Only greet if there is genuinely no history and we haven't triggered yet
         if (stored.length === 0 && !initTriggered.current) {
           initTriggered.current = true;
           sendToAtlas("__atlas_init__", true);
         }
       })
       .catch(() => {
+        if (cancelled) return;
         setHistoryLoaded(true);
-        // If we can't load, still try to greet on first open
-        if (!initTriggered.current) {
-          initTriggered.current = true;
-          sendToAtlas("__atlas_init__", true);
-        }
       });
+
+    return () => { cancelled = true; };
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [projectId]);
 
+  const handleReset = async () => {
+    if (!confirm("Clear this conversation and start fresh?")) return;
+    try {
+      await fetch(`/api/projects/${projectId}/atlas-chat`, { method: "DELETE" });
+      setMessages([]);
+      setHistoryLoaded(false);
+      initTriggered.current = false;
+      // Trigger fresh greeting
+      setTimeout(() => {
+        initTriggered.current = true;
+        sendToAtlas("__atlas_init__", true);
+      }, 100);
+    } catch {
+      // swallow
+    }
+  };
+
   const handleSend = () => {
     const text = input.trim();
     if (!text || isStreaming) return;
@@ -226,7 +242,22 @@ export function AtlasChat({ projectId }: AtlasChatProps) {
 
       {/* Messages */}
       {!isEmpty && (
-        <div style={{ flex: 1, overflowY: "auto", padding: "28px 32px" }}>
+        <div style={{ flex: 1, overflowY: "auto", padding: "28px 32px", position: "relative" }}>
+          {/* Reset button — top right, only visible on hover of the area */}
+          <button
+            onClick={handleReset}
+            title="Reset conversation"
+            style={{
+              position: "absolute", top: 12, right: 16,
+              background: "none", border: "none", cursor: "pointer",
+              fontSize: "0.68rem", color: "#d0ccc4", fontFamily: "Outfit, sans-serif",
+              padding: "3px 7px", borderRadius: 4, transition: "color 0.12s",
+            }}
+            onMouseEnter={e => (e.currentTarget.style.color = "#8a8478")}
+            onMouseLeave={e => (e.currentTarget.style.color = "#d0ccc4")}
+          >
+            Reset
+          </button>
           {messages.map((msg, i) => (
             <MessageRow key={i} msg={msg} userInitial={userInitial} />
           ))}