feat(chat): add ActiveChatStreamRunner to persist streams across nav

surfsense_web/components/chat/active-chat-stream-runner.tsx

@@ -0,0 +1,29 @@
+"use client";
+
+import { useEffect } from "react";
+import { chatStreamStore } from "@/lib/chat/stream-engine/store";
+
+/**
+ * Persistent, render-null host for app-wide chat-stream lifecycle.
+ *
+ * Mounted in the workspace shell (``LayoutDataProvider``), it persists across
+ * in-app navigation between workspace routes (``/new-chat`` -> ``/chats`` ->
+ * ``/automations`` and doc-tab switches) and only unmounts on real teardown
+ * (workspace change / app teardown). On that teardown it aborts the single
+ * in-flight turn — this replaces the old chat-page unmount abort, which was
+ * what killed streams on ordinary navigation.
+ *
+ * NOTE: the ``hitl-decision`` bridge and ``useChatSessionStateSync`` stay in
+ * the chat page: both need the currently-viewed thread id (HITL resume can
+ * only be triggered from the page's approval UI), which the shell-level runner
+ * does not cleanly have.
+ */
+export function ActiveChatStreamRunner() {
+	useEffect(() => {
+		return () => {
+			chatStreamStore.abortActive();
+		};
+	}, []);
+
+	return null;
+}