fix(react-hooks): prevent onComplete from firing prematurely when stream disconnects

The onComplete callback in useRealtimeRun and useRealtimeRunWithStreams was
firing whenever the SSE stream ended, regardless of whether the run had
actually completed. This caused issues in self-hosted environments where
reverse proxies (like Traefik) may close idle connections.

The fix changes the condition from checking `run` to checking `run?.finishedAt`,
ensuring onComplete only fires when the run has actually reached a terminal
state.

Fixes #2856

Co-authored-by: nicktrn <nicktrn@users.noreply.github.com>

Author: github-actions[bot]

packages/react-hooks/src/hooks/useRealtime.ts

@@ -149,8 +149,10 @@ export function useRealtimeRun<TTask extends AnyTask>(
   const hasCalledOnCompleteRef = useRef(false);
 
   // Effect to handle onComplete callback
+  // Only call onComplete when the run has actually finished (has finishedAt),
+  // not just when the subscription stream ends (which can happen due to network issues)
   useEffect(() => {
-    if (isComplete && run && options?.onComplete && !hasCalledOnCompleteRef.current) {
+    if (isComplete && run?.finishedAt && options?.onComplete && !hasCalledOnCompleteRef.current) {
       options.onComplete(run, error);
       hasCalledOnCompleteRef.current = true;
     }
@@ -313,8 +315,10 @@ export function useRealtimeRunWithStreams<
   const hasCalledOnCompleteRef = useRef(false);
 
   // Effect to handle onComplete callback
+  // Only call onComplete when the run has actually finished (has finishedAt),
+  // not just when the subscription stream ends (which can happen due to network issues)
   useEffect(() => {
-    if (isComplete && run && options?.onComplete && !hasCalledOnCompleteRef.current) {
+    if (isComplete && run?.finishedAt && options?.onComplete && !hasCalledOnCompleteRef.current) {
       options.onComplete(run, error);
       hasCalledOnCompleteRef.current = true;
     }