harden PWA resume and title fallback

web/src/App.tsx

@@ -162,20 +162,18 @@ const EMPTY_ACTIVE_RUNS: ActiveRunsState = {
 
 function waitForAppForeground() {
   if (typeof document === "undefined" || typeof window === "undefined") return Promise.resolve();
-  if (document.visibilityState !== "hidden" && navigator.onLine !== false) return Promise.resolve();
+  if (document.visibilityState !== "hidden") return Promise.resolve();
 
   return new Promise<void>((resolve) => {
     const finishIfReady = () => {
-      if (document.visibilityState === "hidden" || navigator.onLine === false) return;
+      if (document.visibilityState === "hidden") return;
       document.removeEventListener("visibilitychange", finishIfReady);
       window.removeEventListener("pageshow", finishIfReady);
-      window.removeEventListener("online", finishIfReady);
       resolve();
     };
 
     document.addEventListener("visibilitychange", finishIfReady);
     window.addEventListener("pageshow", finishIfReady);
-    window.addEventListener("online", finishIfReady);
   });
 }
 
@@ -1179,7 +1177,7 @@ export default function App() {
       const message = err instanceof Error ? err.message : String(err);
       if (message.includes("bearer token")) {
         handleAuthFailure(message);
-      } else {
+      } else if (!isRecoverableStreamDisconnect(err)) {
         setError(message);
       }
     } finally {
@@ -1197,7 +1195,7 @@ export default function App() {
       const message = err instanceof Error ? err.message : String(err);
       if (message.includes("bearer token")) {
         handleAuthFailure(message);
-      } else {
+      } else if (!isRecoverableStreamDisconnect(err)) {
         setError(message);
       }
     } finally {
@@ -1234,7 +1232,15 @@ export default function App() {
         suspendChatStreams();
         return;
       }
+      setError((current) => (current && isRecoverableStreamDisconnect(new Error(current)) ? null : current));
       void refreshActiveRuns();
+      void refreshCollections(selectedItemRef.current ?? undefined, false);
+      const currentSelection = selectedItemRef.current;
+      if (currentSelection?.kind === "chat") {
+        void refreshChat(currentSelection.id);
+      } else if (currentSelection?.kind === "search") {
+        void refreshSearch(currentSelection.id);
+      }
     };
     const handlePageShow = () => {
       void refreshActiveRuns();
@@ -2216,6 +2222,7 @@ export default function App() {
 
     while (true) {
       let streamErrorMessage: string | null = null;
+      let replayedAssistantText = "";
       const abortController = new AbortController();
       chatStreamAbortRefs.current.set(chatId, abortController);
 
@@ -2246,6 +2253,7 @@ export default function App() {
             },
             onDelta: (payload) => {
               if (!payload.text) return;
+              replayedAssistantText += payload.text;
               setPendingChatStates((current) => {
                 const pendingState = current[chatId];
                 if (!pendingState) return current;
@@ -2254,7 +2262,7 @@ export default function App() {
                   const isTarget = index === all.length - 1 && message.id.startsWith("temp-assistant-");
                   if (!isTarget) return message;
                   updated = true;
-                  return { ...message, content: message.content + payload.text };
+                  return { ...message, content: replayedAssistantText };
                 });
                 return updated ? { ...current, [chatId]: { messages: nextMessages } } : current;
               });
@@ -2312,35 +2320,23 @@ export default function App() {
         if (shouldResumeStream) {
           try {
             const persistedChat = await retryAfterAppResume(() => getChat(chatId));
-            const userMessageWasAccepted = hasNewPersistedUserMessage(
-              persistedChat,
-              previousMessageIds,
-              content,
-              attachments
-            );
             setError(null);
             if (isCurrentSelection(target)) {
               setSelectedChat(persistedChat);
               setSelectedSearch(null);
             }
-            setPendingChatStates((current) => ({
-              ...current,
-              [chatId]: {
-                messages: persistedChat.messages.concat(
-                  ...(userMessageWasAccepted ? [] : [optimisticUserMessage]),
-                  {
-                    ...optimisticAssistantMessage,
-                    id: `temp-assistant-resume-${Date.now()}`,
-                    content: "",
-                  }
-                ),
-              },
-            }));
 
             // Retrying the same idempotent request either starts an unaccepted
-            // submission or replays the existing backend-owned stream.
+            // submission or replays the existing backend-owned stream. Keep
+            // the current optimistic transcript visible until replay begins.
             continue;
           } catch (resumeError) {
+            if (isRecoverableStreamDisconnect(resumeError)) {
+              setError(null);
+              await waitForAppForeground();
+              await waitForRetry(1000);
+              continue;
+            }
             err = resumeError;
           }
         } else if (streamErrorMessage) {