v 3.0.3

frontend/src/hooks/usePolling.ts

@@ -0,0 +1,17 @@
+import { useEffect, useRef } from "react";
+
+export function usePolling(
+  callback: () => void | Promise<void>,
+  intervalMs: number,
+  enabled = true,
+) {
+  const cbRef = useRef(callback);
+  cbRef.current = callback;
+
+  useEffect(() => {
+    if (!enabled) return;
+    cbRef.current();
+    const id = setInterval(() => cbRef.current(), intervalMs);
+    return () => clearInterval(id);
+  }, [intervalMs, enabled]);
+}

frontend/src/hooks/useSSE.ts

@@ -0,0 +1,26 @@
+import { useEffect, useRef } from "react";
+
+export function useSSE<T>(
+  url: string,
+  onMessage: (data: T) => void,
+  enabled = true,
+) {
+  const cbRef = useRef(onMessage);
+  cbRef.current = onMessage;
+
+  useEffect(() => {
+    if (!enabled) return;
+
+    const es = new EventSource(url);
+    es.onmessage = (e) => {
+      try {
+        cbRef.current(JSON.parse(e.data));
+      } catch { /* ignore parse errors */ }
+    };
+    es.onerror = () => {
+      es.close();
+    };
+
+    return () => es.close();
+  }, [url, enabled]);
+}