fix: use inequality instead of greater than for timestamp check

Addresses PR feedback to rely on timestamp inequality since it is more robust to clock issues and timestamp resolution when saving on the backend.

src/App.tsx

@@ -108,6 +108,8 @@ export function App() {
   const loadVersionRef = useRef(0);
   const themeSyncFrameRef = useRef<number | null>(null);
   const toastTimeoutRef = useRef<number | null>(null);
+  const loadedUpdatedAtRef = useRef<string | null>(null);
+  const inFlightTitleSaveRef = useRef<Promise<void> | null>(null);
 
   const activeDrawing = useMemo(
     () => drawings.find((drawing) => drawing.id === activeId) ?? null,
@@ -141,6 +143,7 @@ export function App() {
       body: JSON.stringify(nextScene),
     })
       .then((body) => {
+        loadedUpdatedAtRef.current = body.drawing.updatedAt;
         setDrawings((current) => replaceMeta(current, body.drawing));
         if (isManual) {
           setToastMessage("Saved");
@@ -230,6 +233,7 @@ export function App() {
         currentIdRef.current = drawing.id;
         currentTitleRef.current = drawing.title;
         latestSceneRef.current = nextScene;
+        loadedUpdatedAtRef.current = drawing.updatedAt;
 
         setDrawings(sortDrawings(list));
         setActiveId(drawing.id);
@@ -323,18 +327,22 @@ export function App() {
       return;
     }
 
-    try {
-      const body = await requestJson<{ ok: true; drawing: DrawingMeta }>(`/api/drawings/${drawingId}`, {
-        method: "PUT",
-        body: JSON.stringify({ title: currentTitleRef.current }),
-      });
-
+    const promise = requestJson<{ ok: true; drawing: DrawingMeta }>(`/api/drawings/${drawingId}`, {
+      method: "PUT",
+      body: JSON.stringify({ title: currentTitleRef.current }),
+    }).then((body) => {
       currentTitleRef.current = body.drawing.title;
+      loadedUpdatedAtRef.current = body.drawing.updatedAt;
       setActiveTitle(body.drawing.title);
       setDrawings((current) => replaceMeta(current, body.drawing));
-    } catch (renameError) {
+    }).catch((renameError) => {
       setError(renameError instanceof Error ? renameError.message : "Rename failed");
-    }
+    }).finally(() => {
+      inFlightTitleSaveRef.current = null;
+    });
+
+    inFlightTitleSaveRef.current = promise;
+    await promise;
   }, []);
 
   const syncThemeTokens = useCallback(() => {
@@ -411,6 +419,32 @@ export function App() {
     };
   }, []);
 
+  useEffect(() => {
+    const interval = window.setInterval(() => {
+      void refreshList();
+    }, 5000);
+
+    return () => {
+      window.clearInterval(interval);
+    };
+  }, [refreshList]);
+
+  useEffect(() => {
+    if (
+      activeDrawing &&
+      loadedUpdatedAtRef.current &&
+      activeDrawing.updatedAt !== loadedUpdatedAtRef.current &&
+      !inFlightSaveRef.current &&
+      !inFlightTitleSaveRef.current
+    ) {
+      if (timeoutRef.current !== null) {
+        clearTimeout(timeoutRef.current);
+        timeoutRef.current = null;
+      }
+      void loadDrawing(activeDrawing.id);
+    }
+  }, [activeDrawing, loadDrawing]);
+
   useEffect(() => {
     if (!scene || loading) {
       return;